Answer url when choosing canonical questions

[Ffisegydd]

At the moment, sopython-site supports either:

i. A question id, or
ii. A question url

when choosing canonical links.

Sometimes the answer to a question is more famous than the question itself, as such some people may inadvertently use an answer url, which will cause some form of error (not tested to find out what particular type) when the regex fails to match the answer url.

[Ffisegydd]

If you need an answer regex, you could steal the one that Jerry and poke helped me put together for nidaba from here