CrossEPG_Main.setup: expect additional arguments

This function is exported as plugin entry point
so it should expect additional arguments being
passed.

Alternative solution might have been:

--- a/src/enigma2/python/plugin.py
+++ b/src/enigma2/python/plugin.py
@@ -5,7 +5,7 @@ from Plugins.Plugin import PluginDescriptor

 def setup(menuid, **kwargs):
        if menuid == "setup":
-               return [("CrossEPG", crossepg_main.setup, "crossepg", None)]
+               return [("CrossEPG", call_setup, "crossepg", None)]
        else:
                return []

Which avoids exporting a class member.