throw error if riot returns no summoners
throw error if riot returns no summoners

PhunStyle/Gravebot,PhunStyle/Gravebot,etp12/Gravebot,freevortex/teabot,A-lxe/Gravebot,A-lxe/Gravebot,gw2code/Glenna,gw2code/Glenna,Gravebot/Gravebot,PhunStyle/Gravebot,stratsco/stratsbot,gw2code/Glenna,stratsco/stratsbot,freevortex/teabot,A-lxe/Gravebot,etp12/Gravebot,etp12/Gravebot,Gravebot/Gravebot,Gravebot/Gravebot