Matchmaking buttons link to other channels

[ghost]

Tried to join the channel for Javascript, and I saw the unread notification pop up in Investing. Happened two times before the third click got Javascript working again.

This could just be a Slack client bug, but better safe than sorry to take a look in case someone else hits this.

(above image is post two clicks in #javascript)

[ghost]

This still could be a client-side bug that we can't control, but I think we should go through one or two more matching cycles and see if anyone else hits this before closing it.