Don't translate debug logs and warnings

Warnings that are going to the journal should be not translated:
they're not user visible, and translating them would just make
bug reporting harder (as now the developers need to understand
what the warning is saying)

https://bugzilla.gnome.org/show_bug.cgi?id=707897

src/core/core.c

@@ -155,7 +155,7 @@ meta_core_get (Display *xdisplay,
         break;
 
       default:
-        meta_warning(_("Unknown window information request: %d"), request);
+        meta_warning("Unknown window information request: %d\n", request);
     }
 
     request = va_arg (args, MetaCoreGetType);