It's very easy to forget to add `require 'rails_helper'` at the top of every core/plugin spec file, and omissions can cause some very confusing/sporadic errors.
By setting this flag in `.rspec`, we can remove the need for `require 'rails_helper'` entirely.
This is required for people using apps with custom protocols. We still verify the entire URL (including protocol) against the site setting value.
Refactored wildcard_url_checker so that it always returns a boolean, rather than sometimes returning a regex match.