Update the selector for finding the link to the parent message

[balpha]

https://meta.stackexchange.com/questions/412436/replying-to-smokey-reports-via-chat-is-broken

This change is completely untested and it's been years since I've looked at ChatExchange. Take this PR more as a "FYI I think this is where the problem is" pointer. It looks like this should be all that's necessary to make it work again, but that's purely from glancing at things.

[Manishearth]

Might not have time to test this soon, if someone else wants to test it out and verify.

[Manishearth]

Actually, from Charcoal-SE/SmokeDetector#14870, this is sufficent for me:

@balpha's #186, when cherry-picked onto our fork, fixes the loading of the reply info.

[makyen]

Merging this appears to have been fine, and probably more in line with where SE intends to go in the future. However, SE is currently serving the HTML with that element having both the reply-info-container and reply-info classes, so the code should with and without the change. This is an adjustment on SE's part, as for a time the HTML did not have reply-info as a class on that element. SE made this adjustment in order to maintain backward compatibility, once they were informed that changing the class name broke things.