Fix failing backup filename spec for RCs
Fix failing backup filename spec for RCs

See http://rubular.com/r/9oI7K8b773 for more details.

mmkassem/gitlabhq,stoplightio/gitlabhq,iiet/iiet-git,jirutka/gitlabhq,dplarson/gitlabhq,stoplightio/gitlabhq,dplarson/gitlabhq,t-zuehlsdorff/gitlabhq,jirutka/gitlabhq,mmkassem/gitlabhq,mmkassem/gitlabhq,t-zuehlsdorff/gitlabhq,dreampet/gitlab,dreampet/gitlab,mmkassem/gitlabhq,axilleas/gitlabhq,dplarson/gitlabhq,dreampet/gitlab,jirutka/gitlabhq,dreampet/gitlab,iiet/iiet-git,axilleas/gitlabhq,iiet/iiet-git,stoplightio/gitlabhq,axilleas/gitlabhq,t-zuehlsdorff/gitlabhq,t-zuehlsdorff/gitlabhq,iiet/iiet-git,stoplightio/gitlabhq,axilleas/gitlabhq,jirutka/gitlabhq,dplarson/gitlabhq