Reduce noise for test_url_spec.rb

What does this merge request do and why?

This minor MR fixes a broken window with spec/lib/gdk/test_url_spec.rb:

Before

$ make rspec
Bundle check passed.
RSpec: ............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................=> Waiting until http://127.0.0.1:3000/users/sign_in is ready..=> http://127.0.0.1:3000/users/sign_in does not appear to be up. Waited 0.0 second(s).
..=> Waiting until http://127.0.0.1:3000/users/sign_in is ready.......................................................................................................................

Finished in 3.26 seconds (files took 0.51065 seconds to load)
1059 examples, 0 failures

After

$ make rspec
Bundle check passed.
RSpec: ...................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

Finished in 3.61 seconds (files took 0.48774 seconds to load)
1059 examples, 0 failures

Impacted categories

The following categories relate to this merge request:

• gdk-reliability - e.g. When a GDK action fails to complete.
• gdk-usability - e.g. Improvements or suggestions around how the GDK functions.
• gdk-performance - e.g. When a GDK action is slow or times out.

Merge request checklist

• This change is backward compatible. If not, please include steps to communicate to our users.
• Tests added for new functionality. If not, please raise an issue to follow-up.
• Documentation added/updated, if needed.
• Announcement added, if change is notable.
• gdk doctor test added, if needed.
• Add the ~highlight label if this MR should be included in the CHANGELOG.md.