Merge branch 'emailsonpush-prefix' into 'master'

Prefix EmailsOnPush email subject with `[Git]`.

Fixes internal issue https://dev.gitlab.org/gitlab/gitlabhq/issues/2112.

See merge request !701

CHANGELOG

@@ -19,6 +19,7 @@ v 7.12.0 (unreleased)
   - Add a note when an Issue or Merge Request's title changes
   - Consistently refer to MRs as either Accepted or Rejected.
   - Add Accepted and Rejected tabs to MR lists.
+  - Prefix EmailsOnPush email subject with `[Git]`.
 
 v 7.11.2
   - no changes

app/mailers/emails/projects.rb

@@ -93,7 +93,8 @@ module Emails
           "pushed to"
         end
 
-      @subject = "[#{@project.path_with_namespace}]"
+      @subject = "[Git]"
+      @subject << "[#{@project.path_with_namespace}]"
       @subject << "[#{@ref_name}]" if action == :push
       @subject << " "