These tests were checking the URLs of documents and images pointed to
the URL generated by the `attachment.url` method. In order to do so, we
were running database queries after starting the process running the
browser, which is sometimes causing database inconsistencies when
running the tests.
So I'm simply removing the URL check. The tests are slightly less useful
now, but it isn't like they were 100% right in the first place. After
all, if the `attachment.url` method wasn't working properly, the tests
were still passing.
c3b3bd4502