ffi-yajl/json_gem deprecation warnings

I'm on CentOS 7, vmware VM on esxi 5.5, using the omnibus gitlab install. After the upgrade, I get this:

[root@gitlab-dev ~]# gitlab-ctl reconfigure
the ffi-yajl and yajl-ruby gems have incompatible C libyajl libs and should not be loaded in the same Ruby VM
falling back to ffi which might work (or might not, no promises)
ffi-yajl/json_gem is deprecated, these monkeypatches will be dropped shortly
Starting Chef Client, version 11.12.2

Here is my env:

[root@gitlab-dev ~]# gitlab-rake gitlab:env:info

System information
System:		
Current User:	git
Using RVM:	no
Ruby Version:	2.1.4p265
Gem Version:	2.2.1
Bundler Version:1.5.3
Rake Version:	10.3.2
Sidekiq Version:2.17.8

GitLab information
Version:	7.6.1
Revision:	0286222
Directory:	/opt/gitlab/embedded/service/gitlab-rails
DB Adapter:	postgresql
URL:		https://gitlab-test.intello.com
HTTP Clone URL:	https://gitlab-test.intello.com/some-project.git
SSH Clone URL:	git@gitlab-test.intello.com:some-project.git
Using LDAP:	no
Using Omniauth:	no

GitLab Shell
Version:	2.4.0
Repositories:	/var/opt/gitlab/git-data/repositories
Hooks:		/opt/gitlab/embedded/service/gitlab-shell/hooks/
Git:		/opt/gitlab/embedded/bin/git