template1 as default database for Postgres

Fixes #402 (https://github.com/doctrine/DoctrineBundle/issues/402) by connecting by default to 'template1' instead of the database with the same name as the user (Postgre default in case of no dbname).

lib/Doctrine/DBAL/Driver/PDOPgSql/Driver.php

@@ -60,6 +60,9 @@ class Driver implements \Doctrine\DBAL\Driver
         if (isset($params['dbname'])) {
             $dsn .= 'dbname=' . $params['dbname'] . ' ';
         }
+        else {
+            $dsn .= 'dbname=template1' . ' ';
+        }
 
         return $dsn;
     }