Message room scroll is not at bottom when opening a room

Summary

When the user switches from a room to another, the message room scroll is not at the bottom and the user needs to scroll it down to see the last message received.

Environment

• Windows - HipChat 4.0
• Linux 4.0
• Mac - HipChat 4.0

Steps to Reproduce

1. Open a room and start chatting.
2. Go to another room.
3. Once you receive a message in the first room, open it again.

Expected Results

When you open the first room for the second time, it shows the last messages received.

Actual Results

When you open the first room for the second time, it does not show the last message received because the chat screen is scrolled up. You need to scroll it down to see the message.