Fix build failure links in Slack
Fix build failure links in Slack

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