add socket.io back, cleanup

Change-Id: I74e043268c23fb45371f1e397ca2931ca177afc3
diff --git a/client/package.json b/client/package.json
index 191dd7f..5c4cc03 100644
--- a/client/package.json
+++ b/client/package.json
@@ -17,7 +17,7 @@
     "react-emoji-render": "^1.2.4",
     "react-router-dom": "^5.2.0",
     "react-sound": "^1.2.0",
-    "socket.io-client": "^2.3.0"
+    "socket.io-client": "^4.0.1"
   },
   "devDependencies": {
     "@babel/plugin-transform-runtime": "^7.13.15",