tests: Accept more IPs in login tests
tests: Accept more IPs in login tests

We run the login tests not only on our own test VMs but also as part of
distro package validation testing.  Stop hardcoding the IP we use in our
test framework.

Out of lack of interest in writing a more elaborate regexp, the code
will accept IPv4 IPs or IPv6 IPs which contain :: in them (which should
cover almost anything we're likely to see in a testing environment).

Fixes #14874
Closes #14887

mvollmer/cockpit,mvollmer/cockpit,cockpit-project/cockpit,deryni/cockpit,deryni/cockpit,deryni/cockpit,cockpit-project/cockpit,garrett/cockpit,garrett/cockpit,mvollmer/cockpit,martinpitt/cockpit,deryni/cockpit,cockpit-project/cockpit,martinpitt/cockpit,deryni/cockpit,mvollmer/cockpit,mvollmer/cockpit,martinpitt/cockpit,garrett/cockpit,martinpitt/cockpit,martinpitt/cockpit,garrett/cockpit,cockpit-project/cockpit,deryni/cockpit,cockpit-project/cockpit,garrett/cockpit,deryni/cockpit