Added maxlength for nicknames (#3186)

webapp/utils/constants.jsx

@@ -739,6 +739,7 @@ export default {
     MAX_TEAMNAME_LENGTH: 15,
     MIN_USERNAME_LENGTH: 3,
     MAX_USERNAME_LENGTH: 22,
+    MAX_NICKNAME_LENGTH: 22,
     MIN_PASSWORD_LENGTH: 5,
     MAX_PASSWORD_LENGTH: 50,
     MIN_TRIGGER_LENGTH: 1,