Import url imports are not allowed from that URL

Summary

Importing projects from Gitlab v7.2.1 using the "Repo by URL" feature using v9.1.4 is failing with "Import url imports are not allowed from that URL" error. This function was previously working in 8.1.x but now fails after an upgrade.

Steps to reproduce

1. Go to group
2. Go to New Project
3. Select Import project from > (git) Repo by URL
4. Enter the HTTP URL and your credentials to access another v7.2.1 Gitlab repository
5. Select Create Project

What is the current bug behavior?

An error shows "Import url imports are not allowed from that URL", "Unable to save project. Error: Import url imports are not allowed from that URL"

What is the expected correct behavior?

Import should complete and page should refresh with new imported repository

Relevant logs and/or screenshots

See attached...

Results of GitLab environment info

Expand for output related to GitLab environment info

System information
System:		Ubuntu 16.04
Current User:	git
Using RVM:	no
Ruby Version:	2.3.3p222
Gem Version:	2.6.6
Bundler Version:1.13.7
Rake Version:	10.5.0
Redis Version:	3.2.5
Git Version:	2.11.1
Sidekiq Version:4.2.7
GitLab information
Version:	9.1.4
Revision:	fed799a
Directory:	/opt/gitlab/embedded/service/gitlab-rails
DB Adapter:	postgresql
URL:		https://git.[edited]
HTTP Clone URL:	https://git.[edited]/some-group/some-project.git
SSH Clone URL:	git@git.[edited]:some-group/some-project.git
Using LDAP:	no
Using Omniauth:	no
GitLab Shell
Version:	5.0.2
Repository storage paths:

• default: /var/opt/gitlab/git-data/repositories Hooks: /opt/gitlab/embedded/service/gitlab-shell/hooks Git: /opt/gitlab/embedded/bin/git

Results of GitLab application Check

Expand for output related to the GitLab application check

Checking GitLab Shell ...
GitLab Shell version >= 5.0.2 ? ... OK (5.0.2)
Repo base directory exists?
default... yes
Repo storage directories are symlinks?
default... no
Repo paths owned by git:git?
default... yes
Repo paths access is drwxrws---?
default... yes
hooks directories in repos are links: ...
2/3 ... ok
2/5 ... ok
3/6 ... ok
8/7 ... ok
9/8 ... ok
3/9 ... repository is empty
10/10 ... ok
12/11 ... ok
12/12 ... ok
13/13 ... ok
13/14 ... ok
13/15 ... ok
13/16 ... ok
13/17 ... ok
13/18 ... ok
9/19 ... ok
3/20 ... ok
13/21 ... ok
14/22 ... ok
9/23 ... ok
15/24 ... ok
4/25 ... ok
16/26 ... ok
9/27 ... ok
9/30 ... ok
9/31 ... ok
9/32 ... ok
9/33 ... ok
9/34 ... ok
9/35 ... ok
9/36 ... ok
9/37 ... ok
9/38 ... ok
9/39 ... ok
9/40 ... ok
9/41 ... ok
9/42 ... ok
9/43 ... ok
9/44 ... ok
17/45 ... ok
17/46 ... ok
17/47 ... ok
18/48 ... ok
19/49 ... ok
9/50 ... ok
9/51 ... ok
Running /opt/gitlab/embedded/service/gitlab-shell/bin/check
Check GitLab API access: OK
Access to /var/opt/gitlab/.ssh/authorized_keys: OK
Send ping to redis server: OK
gitlab-shell self-check successful
Checking GitLab Shell ... Finished
Checking Sidekiq ...
Running? ... yes
Number of Sidekiq processes ... 1
Checking Sidekiq ... Finished
Checking Reply by email ...
Reply by email is disabled in config/gitlab.yml
Checking Reply by email ... Finished
Checking LDAP ...
LDAP is disabled in config/gitlab.yml
Checking LDAP ... Finished
Checking GitLab ...
Git configured with autocrlf=input? ... yes
Database config exists? ... yes
All migrations up? ... yes
Database contains orphaned GroupMembers? ... no
GitLab config exists? ... yes
GitLab config outdated? ... no
Log directory writable? ... yes
Tmp directory writable? ... yes
Uploads directory setup correctly? ... yes
Init script exists? ... skipped (omnibus-gitlab has no init script)
Init script up-to-date? ... skipped (omnibus-gitlab has no init script)
projects have namespace: ...
2/3 ... yes
2/5 ... yes
3/6 ... yes
8/7 ... yes
9/8 ... yes
3/9 ... yes
10/10 ... yes
12/11 ... yes
12/12 ... yes
13/13 ... yes
13/14 ... yes
13/15 ... yes
13/16 ... yes
13/17 ... yes
13/18 ... yes
9/19 ... yes
3/20 ... yes
13/21 ... yes
14/22 ... yes
9/23 ... yes
15/24 ... yes
4/25 ... yes
16/26 ... yes
9/27 ... yes
9/30 ... yes
9/31 ... yes
9/32 ... yes
9/33 ... yes
9/34 ... yes
9/35 ... yes
9/36 ... yes
9/37 ... yes
9/38 ... yes
9/39 ... yes
9/40 ... yes
9/41 ... yes
9/42 ... yes
9/43 ... yes
9/44 ... yes
17/45 ... yes
17/46 ... yes
17/47 ... yes
18/48 ... yes
19/49 ... yes
9/50 ... yes
9/51 ... yes
Redis version >= 2.8.0? ... yes
Ruby version >= 2.1.0 ? ... yes (2.3.3)
Your git bin path is "/opt/gitlab/embedded/bin/git"
Git version >= 2.7.3 ? ... yes (2.11.1)
Active users: 7
Checking GitLab ... Finished

Possible fixes

Import from the same v7.2.1 GitLab Was working in v8.1.x, but we upgraded and now the import is broken.