Merge branch 'sidekiq_gc_start' into 'master'

Run 'GC.start' after every EmailsOnPushWorker job

This change removed a lot of large peaks of the Sidekiq memory growth graph on gitlab.com.

See merge request !1257

CHANGELOG

@@ -2,6 +2,7 @@ v 7.5.0
   - API: Add support for Hipchat (Kevin Houdebert)
   - Add time zone configuration on gitlab.yml (Sullivan Senechal)
   - Fix LDAP authentication for Git HTTP access
+  - Run 'GC.start' after every EmailsOnPushWorker job
   - Fix LDAP config lookup for provider 'ldap'
   - Drop all sequences during Postgres database restore
   - Project title links to project homepage (Ben Bodenmiller)

app/workers/emails_on_push_worker.rb

@@ -21,5 +21,8 @@ class EmailsOnPushWorker
     recipients.split(" ").each do |recipient|
       Notify.repository_push_email(project_id, recipient, author_id, branch, compare).deliver
     end
+  ensure
+    compare = nil
+    GC.start
   end
 end