GDK W32: Fix property setting to correctly use static strings

The strings that are set are static, so g_value_set_static_string() should
be used to set them instead of g_value_set_string().

gdk/win32/gdkproperty-win32.c

@@ -424,9 +424,9 @@ _gdk_win32_screen_get_setting (GdkScreen   *screen,
   else if (strcmp ("gtk-im-module", name) == 0)
     {
       if (_gdk_input_locale_is_ime)
-        g_value_set_string (value, "ime");
+        g_value_set_static_string (value, "ime");
       else
-        g_value_set_string (value, "");
+        g_value_set_static_string (value, "");
 
       return TRUE;
     }