Retain fewer etherpad database backups

These backups were kept locally for convenience of operation. Bup stores
blobs in git so it should be effectively deduping these over time so
wasn't a stress on remote backups. However now we are filling the local
disk with the db backup files.

Address this by reducing the number of local backups to 5 (from 10).

Change-Id: I1765836784752dba2a6f2582801b860fcce4843c

modules/openstack_project/manifests/etherpad.pp

@@ -41,7 +41,7 @@ class openstack_project::etherpad (
     database_host     => $mysql_host,
     database_user     => $mysql_user,
     database_password => $mysql_password,
-    num_backups       => '10',
+    num_backups       => '5',
     require           => Class['etherpad_lite'],
   }
 

modules/openstack_project/manifests/etherpad_dev.pp

@@ -31,6 +31,7 @@ class openstack_project::etherpad_dev (
     database_host     => $mysql_host,
     database_user     => $mysql_user,
     database_password => $mysql_password,
+    num_backups       => '5',
     require           => Class['etherpad_lite'],
   }
 }