Update CHANGELOG.md for 11.6.1
Update CHANGELOG.md for 11.6.1

[ci skip]
stoplightio/gitlabhq,mmkassem/gitlabhq,mmkassem/gitlabhq,stoplightio/gitlabhq,axilleas/gitlabhq,axilleas/gitlabhq,mmkassem/gitlabhq,dreampet/gitlab,iiet/iiet-git,dreampet/gitlab,dreampet/gitlab,axilleas/gitlabhq,axilleas/gitlabhq,mmkassem/gitlabhq,iiet/iiet-git,iiet/iiet-git,iiet/iiet-git,stoplightio/gitlabhq,stoplightio/gitlabhq,dreampet/gitlab