Gist url matching is too restrictive

[AlexDaniel]

<AlexDaniel> c: HEAD https://gist.github.com/c39b3c916525e390e74c6ad050f887a1
<committable6> AlexDaniel, It looks like a URL, but mime type is ‘text/html; charset=utf-8’ while I was expecting something with ‘text/plain’ or ‘perl’ in it. I can only understand raw links, sorry.
<AlexDaniel> wat
<AlexDaniel> committable6 are you out of your mind?
<AlexDaniel> 6c: https://gist.github.com/samcv/c39b3c916525e390e74c6ad050f887a1
<committable6> AlexDaniel, https://gist.github.com/aa6b829395f052bf8dcbaa5dbcad87ea
<AlexDaniel> ah, it didn't match the link

[AlexDaniel]

Also doesn't work with nicknames that have numbers in it.