Call to_s on site.url before attempting to concatenate strings

[benbalter]

We call to_s before we call site.baseurl, but we don't call to_s before we call site.url, meaning if site.url is something other than a string, things blow up.

The specific use case for the to_s here, other than users that set url to something else, is the ability to stub site.url with a Proc that would lazily calculate the URL when called.

[pathawks]

Rubocop thinks the line is too long.
Otherwise LGTM 👍

[parkr]

Test?

[parkr]

In test/test_filters.rb there should be a section for URL-related filters. Throw in something that would break Addressable::URI.parse and just make sure it ends up as a string. I would recommend using URI or some class that has a built-in to_s, or you could build a tiny custom class for this purpose. If you're not able to get to writing a test, I can see about adding one for this myself.

Also a quick fmt error. 😸

[parkr]

Added 2 tests: one for site.url and one to ensure the same behaviour for site.baseurl.

[mattr-]

[parkr]

@jekyllbot: merge +fix