Fix so works with all numeric AudioDB API keys

[wags1]

I'm in the US and have a all numeric AudioDB API key. In order for things to work I need to change a line in lib, helpers, theaudiodb.py and replace the existing code in the line near end of py file with -

endpoint = 'https://www.theaudiodb.com/api/v1/json/%s/%s' % (self.api_key, endpoint)

Is it possible to change the code so that it works no matter what type of AudioDB API key is used so that the manual change is no longer needed? Thanks.