[BUG] No direct messages with new LDAP users

Description:

Since upgrading to 0.66.3 from 0.65.2 a direct chat with new LDAP users is not possible.
Separate rooms will be created for both users in which each user can write and not read and vice versa.

Steps to reproduce:

1. Sync new user from LDAP (e.g. 'Alice')
2. Bob searches for 'Alice' and writes her a new message

Expected behavior:

Alice get the message from Bob and can reply to him.

Actual behavior:

Alice sees a new message, but can't access the room with the message. She will be notified by mail about the message.
If Alice searches for Bob and writes him a message Bob will get the message in a new room which he again can't access. If he tries to enter the room he gets thrown into the one which was created as he initially wrote to Alice.

Server Setup Information:

• Version of Rocket.Chat Server: 0.66.3
• Operating System: CentOS Linux release 7.5.1804
• Deployment Method: tar
• Number of Running Instances: 1
• DB Replicaset Oplog: N/A
• NodeJS Version: v8.11.2
• MongoDB Version: 3.6

Additional context

To bypass this problem both users have to switch to the rocket.chat webbrowser version and the freshly created rooms have to be deleted by an admin. Then a chat between both parties can be stadted and afterwards both users can switch back to the desktop version.

Normally i say would this is a client issue BUT this bug is only reproducible with new or reimported LDAP users so the bug rather seems to be on the server side.

Start by reproducing the LDAP sync, user search, and direct-message flow described in the issue, then trace the server-side creation and lookup of direct-message rooms for newly imported users. Compare the rooms created when Bob messages Alice and when Alice messages Bob; done means both users access one shared room and can exchange messages.