[CLIENT] Links in chat copy wrong

Copying links from chats with friends prepends "event:" to the link.

Reproduction steps:

1. Send someone a link.
2. Rightclick the link.
3. Click "Copy Link".
4. Examine your clipboard. I am on Windows. Happens every time, for links both incoming and outgoing, with different friends and across client restarts. Tested on two computers. I remember it happening at least a few months ago, but didn't think to test or report it.

It turns, for example, https://google.com/ into event:https://google.com/ .