Clean revocation key after starting the instance

hooks.py

@@ -14,4 +14,6 @@ class ServerStartupHook(hooksmanager.Hook):
             session.execute('DELETE Fpasswd F WHERE F revocation_date < %(date)s', {'date': datetime.now()})
             session.commit()
             session.close()
+        # revocation keu must be deleted
+        cleaning_revocation_key(repo)
         repo.looping_task(60 * 60, cleaning_revocation_key, repo)