Change test that would break with Addressable
Change test that would break with Addressable

This test broke when we switched URI processing to Addressable.
We weren't able to make sense of the test or determine what the intent was, so
we decided to instead change the test to cover mailto links

met-office-lab/govspeak,met-office-lab/govspeak,alphagov/govspeak,alphagov/govspeak