Bugfix: Return 0 exit code from RunSqlCommand::execute to fix deprecation notice.

lib/Doctrine/DBAL/Tools/Console/Command/RunSqlCommand.php

@@ -64,5 +64,7 @@ EOT
         }
 
         $output->write(Dumper::dump($resultSet, (int) $depth));
+
+        return 0;
     }
 }