Remove incorrect footer from EmailsOnPush body.

See #1754.

app/mailers/emails/projects.rb

@@ -38,6 +38,8 @@ module Emails
         @subject << @commits.first.title
       end
 
+      @disable_footer = true
+
       mail(from: sender(author_id),
            to: recipient,
            subject: @subject)

app/views/layouts/notify.html.haml

@@ -27,5 +27,5 @@
         - if @target_url
           #{link_to "View it on GitLab", @target_url}
           = email_action @target_url
-        - if @project
+        - if @project && !@disable_footer
           You're receiving this notification because you are a member of the #{link_to_unless @target_url, @project.name_with_namespace, namespace_project_url(@project.namespace, @project)} project team.

spec/mailers/notify_spec.rb

@@ -597,6 +597,10 @@ describe Notify do
     it 'contains a link to the diff' do
       is_expected.to have_body_text /#{diff_path}/
     end
+
+    it 'doesn not contain the misleading footer' do
+      is_expected.not_to have_body_text /you are a member of/
+    end
   end
 
   describe 'email on push with a single commit' do