Fix generate_missing_icons.py with recent GTK

tools/generate_missing_icons.py

@@ -456,6 +456,7 @@ for icon in list_icons:
         destination_path = os.path.join(destination_prefix,"imported-" + theme_name,size_location)
 
         if theme_name != "Lubuntu":
+            if theme_name != "icons":
                 if theme_name != "hicolor":
                     if theme_name != "share":
                         icon_to_copy = Gio.File.new_for_path(path)