Found in debian testing where by default there are no unqualified search
registries installed. As such the test failed as the FIXME said. Now
there is no need for the test to assume anything.
Instead set our own config via CONTAINERS_REGISTRIES_CONF then we can
do exact matches, except that env was not read in the shell completion
code so move some code around to make it read the var in the same way as
podman login/logout.
Signed-off-by: Paul Holzinger <git@holzinger.dev>
Paul Holzinger