flake8: Fix new warnings after flake8 upgrade
flake8: Fix new warnings after flake8 upgrade

felix1m/pyspotify,felix1m/pyspotify,kotamat/pyspotify,mopidy/pyspotify,mopidy/pyspotify,felix1m/pyspotify,jodal/pyspotify,kotamat/pyspotify,kotamat/pyspotify,jodal/pyspotify,jodal/pyspotify