Minor - add exit to avoid continue executing page after an error.

Author: jmontoyaa

main/inc/lib/database.lib.php

@@ -407,6 +407,7 @@ public static function handleError($e)
         } else {
             error_log($e->getMessage());
             api_not_allowed(false, get_lang('GeneralError'));
+            exit;
         }
     }