Update CHANGELOG.md for 9.0.4
Update CHANGELOG.md for 9.0.4

[ci skip]
dreampet/gitlab,mmkassem/gitlabhq,dreampet/gitlab,dplarson/gitlabhq,axilleas/gitlabhq,darkrasid/gitlabhq,t-zuehlsdorff/gitlabhq,mmkassem/gitlabhq,darkrasid/gitlabhq,htve/GitlabForChinese,darkrasid/gitlabhq,dreampet/gitlab,mmkassem/gitlabhq,axilleas/gitlabhq,htve/GitlabForChinese,dreampet/gitlab,jirutka/gitlabhq,jirutka/gitlabhq,stoplightio/gitlabhq,t-zuehlsdorff/gitlabhq,t-zuehlsdorff/gitlabhq,t-zuehlsdorff/gitlabhq,mmkassem/gitlabhq,htve/GitlabForChinese,htve/GitlabForChinese,iiet/iiet-git,stoplightio/gitlabhq,jirutka/gitlabhq,iiet/iiet-git,stoplightio/gitlabhq,stoplightio/gitlabhq,darkrasid/gitlabhq,axilleas/gitlabhq,dplarson/gitlabhq,dplarson/gitlabhq,iiet/iiet-git,dplarson/gitlabhq,iiet/iiet-git,jirutka/gitlabhq,axilleas/gitlabhq