changed manifest.json so that songza keyboard functionality works both on https, and http
changed manifest.json so that songza keyboard functionality works both on https, and http

feedbee/keysocket,noelmansour/keysocket,borismus/keysocket,chrisdeely/keysocket,feedbee/keysocket,ALiangLiang/keysocket,borismus/keysocket,vinyldarkscratch/keysocket,vinyldarkscratch/keysocket,kristianj/keysocket,legionaryu/keysocket,kristianj/keysocket,iver56/keysocket,vladikoff/keysocket,Whoaa512/keysocket