Description:

When running RocketChat in subdir, permalink get wrong URL.

Server Setup Information:

• Version of Rocket.Chat Server: 0.64.1
• Operating System: Ubuntu16.04.4
• Deployment Method(snap/docker/tar/etc): docker (image: rocketchat/rocket.chat:0.64.1)
• Number of Running Instances: 1
• DB Replicaset Oplog:
• Node Version:
• mongoDB Version:

Steps to Reproduce:

1. start docker with environment: ROOT_URL=http://localhost:3000/chat
2. login and post any message in general channel
3. select permalink for the message

Expected behavior:

permalink should be "http://hostname/chat/channel/general?msg=..."

Actual behavior:

permalink shows like "http://hostname/chat/chat/channel/general?msg=...."

(extra subdir "/chat/")

links to any channel in Directory also wrong as above

Relevant logs: