Fix: Mongo.setConnectionOptions was not being set correctly (#13586)

.meteor/packages

@@ -3,8 +3,8 @@
 # 'meteor add' and 'meteor remove' will edit this file for you,
 # but you can also edit it by hand.
 
-rocketchat:cors
 rocketchat:mongo-config
+rocketchat:cors
 
 accounts-facebook@1.3.2
 accounts-github@1.4.2

packages/rocketchat-mongo-config/server/index.js

@@ -1,16 +1,8 @@
 import { Mongo } from 'meteor/mongo';
 
-// Revert change from Meteor 1.6.1 who set ignoreUndefined: true
-// more information https://github.com/meteor/meteor/pull/9444
-let mongoOptions = {
-	ignoreUndefined: false,
-};
-
 const mongoOptionStr = process.env.MONGO_OPTIONS;
 if (typeof mongoOptionStr !== 'undefined') {
-	const jsonMongoOptions = JSON.parse(mongoOptionStr);
+	const mongoOptions = JSON.parse(mongoOptionStr);
 
-	mongoOptions = Object.assign({}, mongoOptions, jsonMongoOptions);
+	Mongo.setConnectionOptions(mongoOptions);
 }
-
-Mongo.setConnectionOptions(mongoOptions);