Added retries for db_sync

If db sync fails, it is never retried leading to errors. So, this
patch adds retries for db_sync to avoid sync fails.

Change-Id: I8778bd1b609bc5458a250111dc0a0f9b2fb52161
Related-Bug: #1628580
Closes-Bug: #1645474
(cherry picked from commit 0fc2099d12)

manifests/db/sync.pp

@@ -27,6 +27,8 @@ class glance::db::sync(
     path        => '/usr/bin',
     user        => 'glance',
     refreshonly => true,
+    try_sleep   => 5,
+    tries       => 10,
     logoutput   => on_failure,
   }