Update CHANGELOG.md for 10.5.1
Update CHANGELOG.md for 10.5.1

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