Ensure that the stored site-url has the protocol specified [ci all]

There's a window between the 0.23.0 and 0.23.1 release where the
site-url could be stored without the defaulting logic present in
0.23.1+ that ensures the protocol was specified in the site-url. This
commit adds another migration that checks that the stored site-url has
the protocol default logic applied. If not it updates the site-url as
needed.

Fixes #5585