Make the gitlab-shell PATH patch idempotent
Make the gitlab-shell PATH patch idempotent

On the second run there will not be an env shebang to replace.

felixbuenemann/omnibus-gitlab,copystudy/omnibus-gitlab,copystudy/omnibus-gitlab,felixbuenemann/omnibus-gitlab,gitlabhq/omnibus-gitlab,aleksandrs-ledovskis/omnibus-gitlab,aleksandrs-ledovskis/omnibus-gitlab,gitlabhq/omnibus-gitlab,felixbuenemann/omnibus-gitlab,aleksandrs-ledovskis/omnibus-gitlab,copystudy/omnibus-gitlab,gitlabhq/omnibus-gitlab,gitlabhq/omnibus-gitlab