Fix haml-lint complain.
Fix haml-lint complain.

app/views/shared/issuable/_sidebar.html.haml:79 [W] SpaceInsideHashAttributes: Hash attribute should end with one space before the closing brace

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