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: Ic6094bb265879bd6ad14beeb3a966a79d4d3b3ea
Closes-Bug: #1628580

manifests/db/sync.pp

@@ -16,6 +16,8 @@ class vitrage::db::sync(
     path        => '/usr/bin',
     user        => 'vitrage',
     refreshonly => true,
+    try_sleep   => 5,
+    tries       => 10,
     subscribe   => [Package['vitrage'], Vitrage_config['database/connection']],
   }