Fail to accept URL as XMLTV source

[petterreinholdtsen]

The problem seem to be in XMLTVSource.init() from script.tvguide/source.py, which have these two lines:

        if not self.xmltvFile or not xbmcvfs.exists(self.xmltvFile):
            raise SourceNotConfiguredException()                            

If only the URL is provided, the add-on refuse to start. If I comment out those lines, the add-on start as it should.