x11/window-props: Do not convert WM_NAME

The WM_NAME property is of type TEXT_PROPERTY, which is supposed to be
returned as UTF-8. Commit 840378ae68 broke that assumption, resulting
in crashes with non-UTF8 locales; however the "fix" of converting from
LATIN1 to UTF8 is wrong as well, as the conversion will spit out garbage
when the input encoding isn't actually LATIN1.

Now that the original issue in text_property_to_utf8() has been fixed,
we can simply revert the relevant bits of commit d62491f46e.

https://gitlab.gnome.org/GNOME/mutter/merge_requests/227


(cherry picked from commit 62775d1913)

src/x11/window-props.c

@@ -645,10 +645,7 @@ reload_wm_name (MetaWindow    *window,
 
   if (value->type != META_PROP_VALUE_INVALID)
     {
-      g_autofree gchar *title = g_convert (value->v.str, -1,
-                                           "UTF-8", "LATIN1",
-                                           NULL, NULL, NULL);
-      set_window_title (window, title);
+      set_window_title (window, value->v.str);
 
       meta_verbose ("Using WM_NAME for new title of %s: \"%s\"\n",
                     window->desc, window->title);