Reduce local db backup retention to 10 days

This reduces overall backups by a third saving space on local disk. This
puts a greater reliance on offsite backups but we need those working
anyways.

Change-Id: I0397092646866fad1b828032a362f6814b88f26e

modules/openstack_project/manifests/etherpad.pp

@@ -41,6 +41,7 @@ class openstack_project::etherpad (
     database_host     => $mysql_host,
     database_user     => $mysql_user,
     database_password => $mysql_password,
+    num_backups       => '10',
     require           => Class['etherpad_lite'],
   }
 

modules/openstack_project/manifests/gerrit.pp

@@ -203,6 +203,7 @@ class openstack_project::gerrit (
     database_user     => 'gerrit2',
     database_password => $mysql_password,
     dest_dir          => '/home/gerrit2/mysql_backups',
+    num_backups       => '10',
     require           => Class['::gerrit'],
   }