clean code

packages/app/src/server/crowi/index.js

@@ -308,10 +308,6 @@ Crowi.prototype.scanRuntimeVersions = async function() {
   });
 };
 
-Crowi.prototype.getSocketIoService = function() {
-  return this.socketIoService;
-};
-
 Crowi.prototype.getSlack = function() {
   return this.slack;
 };