Suppress warning about missing `.gitlab-ci.yml` if builds are disabled
Suppress warning about missing `.gitlab-ci.yml` if builds are disabled

When user disables GitLab Ci Service in project's settings then warning
about missing `.gitlab-ci.yml` file should be supressed. This a matter
of user experience as stated in #3761 (closes #3761).

koreamic/gitlabhq,LUMC/gitlabhq,darkrasid/gitlabhq,yatish27/gitlabhq,mr-dxdy/gitlabhq,koreamic/gitlabhq,openwide-java/gitlabhq,cui-liqiang/gitlab-ce,louahola/gitlabhq,larryli/gitlabhq,mrb/gitlabhq,ttasanen/gitlabhq,SVArago/gitlabhq,jirutka/gitlabhq,t-zuehlsdorff/gitlabhq,Soullivaneuh/gitlabhq,jrjang/gitlab-ce,htve/GitlabForChinese,daiyu/gitlab-zh,jrjang/gitlab-ce,yatish27/gitlabhq,dwrensha/gitlabhq,htve/GitlabForChinese,openwide-java/gitlabhq,allysonbarros/gitlabhq,iiet/iiet-git,duduribeiro/gitlabhq,larryli/gitlabhq,dplarson/gitlabhq,dwrensha/gitlabhq,dplarson/gitlabhq,LUMC/gitlabhq,openwide-java/gitlabhq,Datacom/gitlabhq,martijnvermaat/gitlabhq,Datacom/gitlabhq,Soullivaneuh/gitlabhq,shinexiao/gitlabhq,cui-liqiang/gitlab-ce,Soullivaneuh/gitlabhq,darkrasid/gitlabhq,allysonbarros/gitlabhq,Datacom/gitlabhq,koreamic/gitlabhq,jirutka/gitlabhq,daiyu/gitlab-zh,openwide-java/gitlabhq,t-zuehlsdorff/gitlabhq,yatish27/gitlabhq,allysonbarros/gitlabhq,t-zuehlsdorff/gitlabhq,SVArago/gitlabhq,axilleas/gitlabhq,jirutka/gitlabhq,mmkassem/gitlabhq,axilleas/gitlabhq,yatish27/gitlabhq,mmkassem/gitlabhq,SVArago/gitlabhq,screenpages/gitlabhq,SVArago/gitlabhq,louahola/gitlabhq,darkrasid/gitlabhq,dreampet/gitlab,mr-dxdy/gitlabhq,axilleas/gitlabhq,stoplightio/gitlabhq,allysonbarros/gitlabhq,htve/GitlabForChinese,dreampet/gitlab,axilleas/gitlabhq,shinexiao/gitlabhq,LUMC/gitlabhq,mmkassem/gitlabhq,larryli/gitlabhq,martijnvermaat/gitlabhq,icedwater/gitlabhq,duduribeiro/gitlabhq,dreampet/gitlab,iiet/iiet-git,Datacom/gitlabhq,cui-liqiang/gitlab-ce,dwrensha/gitlabhq,jrjang/gitlabhq,koreamic/gitlabhq,larryli/gitlabhq,mrb/gitlabhq,stoplightio/gitlabhq,shinexiao/gitlabhq,jrjang/gitlab-ce,iiet/iiet-git,jrjang/gitlabhq,jirutka/gitlabhq,louahola/gitlabhq,daiyu/gitlab-zh,mmkassem/gitlabhq,dreampet/gitlab,mr-dxdy/gitlabhq,dwrensha/gitlabhq,jrjang/gitlab-ce,screenpages/gitlabhq,martijnvermaat/gitlabhq,jrjang/gitlabhq,icedwater/gitlabhq,dplarson/gitlabhq,darkrasid/gitlabhq,duduribeiro/gitlabhq,daiyu/gitlab-zh,ttasanen/gitlabhq,louahola/gitlabhq,martijnvermaat/gitlabhq,screenpages/gitlabhq,iiet/iiet-git,htve/GitlabForChinese,stoplightio/gitlabhq,dplarson/gitlabhq,mrb/gitlabhq,cui-liqiang/gitlab-ce,Soullivaneuh/gitlabhq,duduribeiro/gitlabhq,icedwater/gitlabhq,LUMC/gitlabhq,ttasanen/gitlabhq,icedwater/gitlabhq,mr-dxdy/gitlabhq,stoplightio/gitlabhq,jrjang/gitlabhq,screenpages/gitlabhq,t-zuehlsdorff/gitlabhq,shinexiao/gitlabhq,ttasanen/gitlabhq,mrb/gitlabhq