rpdata-server: Changed endpoint from /query to /graphql

cmd/rpdata-server/main.go

@@ -21,8 +21,8 @@ func main() {
 		log.Fatalln("Failed to init store:", err)
 	}
 
-	http.Handle("/", handler.Playground("RPData API", "/query"))
-	http.Handle("/query", queryHandler())
+	http.Handle("/", handler.Playground("RPData API", "/graphql"))
+	http.Handle("/graphql", queryHandler())
 
 	go updateCharacters()