add getArtistInfo stub

server/ctrlsubsonic/handlers_by_folder.go

@@ -204,3 +204,7 @@ func (c *Controller) ServeSearchTwo(r *http.Request) *spec.Response {
 	sub.SearchResultTwo = results
 	return sub
 }
+
+func (c *Controller) ServeGetArtistInfo(r *http.Request) *spec.Response {
+	return spec.NewResponse()
+}