JIRA integration does not produce issue links

Summary

With JIRA integration enabled we see comments in our JIRA cards for mentions in git, but no "mentioned on" links in the Issue Links section of the JIRA card.

Steps to reproduce

For us simply:

• Turn on git integration. The credentials for the user are for a newly created user with write access to the JIRA space.

GitLab Enterprise Edition 12.10.14-ee Jira v8.5.5

What is the current bug behavior?

What is the expected correct behavior?

Relevant logs and/or screenshots

Output of checks

Results of GitLab environment info

Expand for output related to GitLab environment info

System information
System:		
Proxy:		no
Current User:	git
Using RVM:	no
Ruby Version:	2.6.6p146
Gem Version:	2.7.10
Bundler Version:1.17.3
Rake Version:	12.3.3
Redis Version:	5.0.7
Git Version:	2.26.2
Sidekiq Version:5.2.7
Go Version:	unknown
GitLab information
Version:	12.10.14-ee
Revision:	f64cd73fb77
Directory:	/opt/gitlab/embedded/service/gitlab-rails
DB Adapter:	PostgreSQL
DB Version:	11.7
URL:		https://domain.name
HTTP Clone URL:	https://domain.name/some-group/some-project.git
SSH Clone URL:	git@domain.name:some-group/some-project.git
Elasticsearch:	no
Geo:		no
Using LDAP:	yes
Using Omniauth:	yes
Omniauth Providers: 
GitLab Shell
Version:	12.2.0
Repository storage paths:
- default: 	/var/opt/gitlab/git-data/repositories
GitLab Shell path:		/opt/gitlab/embedded/service/gitlab-shell
Git:		/opt/gitlab/embedded/bin/git