Make /warn break links

After creating a dedicated /linkbreak command, Zarel recommended that instead I focus on making /warn break links instead. I did that and with this addition /warn breaks links, making them unclickable.
Merge pull request #631 from Quarkiki/patch-1

Make /warn break links
updates
Merge remote-tracking branch 'upstream/master'
Merge branch 'master' of https://github.com/awolffromspace/Pokemon-Showdown