Try to check if branch diverged explicitly
Try to check if branch diverged explicitly

Feedback:
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/7237#note_21627134

jirutka/gitlabhq,iiet/iiet-git,dplarson/gitlabhq,darkrasid/gitlabhq,mmkassem/gitlabhq,mmkassem/gitlabhq,dplarson/gitlabhq,htve/GitlabForChinese,dplarson/gitlabhq,t-zuehlsdorff/gitlabhq,mmkassem/gitlabhq,t-zuehlsdorff/gitlabhq,htve/GitlabForChinese,darkrasid/gitlabhq,LUMC/gitlabhq,darkrasid/gitlabhq,openwide-java/gitlabhq,jirutka/gitlabhq,LUMC/gitlabhq,htve/GitlabForChinese,stoplightio/gitlabhq,openwide-java/gitlabhq,dreampet/gitlab,stoplightio/gitlabhq,dplarson/gitlabhq,axilleas/gitlabhq,dreampet/gitlab,openwide-java/gitlabhq,axilleas/gitlabhq,stoplightio/gitlabhq,jirutka/gitlabhq,axilleas/gitlabhq,stoplightio/gitlabhq,LUMC/gitlabhq,dreampet/gitlab,t-zuehlsdorff/gitlabhq,iiet/iiet-git,darkrasid/gitlabhq,openwide-java/gitlabhq,iiet/iiet-git,iiet/iiet-git,htve/GitlabForChinese,LUMC/gitlabhq,mmkassem/gitlabhq,jirutka/gitlabhq,axilleas/gitlabhq,t-zuehlsdorff/gitlabhq,dreampet/gitlab