Use correct i18n module

wrong_layout/plugin.py

@@ -5,12 +5,8 @@ from gajim.common import app
 
 from gajim.plugins import GajimPlugin
 from gajim.plugins.helpers import log_calls
+from gajim.plugins.plugins_i18n import _
 
-# Since Gajim 1.1.0 _() has to be imported
-try:
-    from gajim.common.i18n import _
-except ImportError:
-    pass
 
 class WrongLayoutPlugin(GajimPlugin):
     @log_calls('WrongLayoutPlugin')