Description:

When Markdown is enabled (under General->Messages) - the following do not work:
@mentions
Announcement text

Steps to reproduce:

1. Change markdown from Original to Markdown (in the markdown menu). Attempt to do a @mention or set a room announcement.

Expected behavior:

Mentions properly alert the users. Announcement text is visible.

Actual behavior:

Mentions do not work. Announcement bar is blue with no text.

Server Setup Information:

• Version of Rocket.Chat Server: 0.67
• Operating System: Ubuntu 16.04
• Deployment Method: Docker
• Number of Running Instances: 1
• DB Replicaset Oplog:
• NodeJS Version:
• MongoDB Version:

Additional context

Relevant logs: