Fixed: backup.pl doesn't work with PostgreSQL unix sockets (bug#10430).
Squashed commit of the following:

commit 2dc7f59a560fa595c537f4a3c8eeda1591549549
Author: s7design <otrs@s7designcreative.com>
Date:   Tue May 20 16:41:04 2014 +0200

    Changed backup.pl and restore.pl for PostrgreSQL when it is used unix socket