Fix spec in shell_spec.rb
Fix spec in shell_spec.rb

The spec for "#add_key does nothing" would always have passed,
since the expectation was on both the wrong object and message.

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