dns: Remove invalid hostnames from unit test
dns: Remove invalid hostnames from unit test

Periods are not allowed in hostnames. The test was leftover from when
containers weren't individually addressable, and were given hostnames
based on their index in the "Service" wrapping them.

kelda/kelda,kelda/kelda,LuiseV/quilt,LuiseV/quilt,LuiseV/quilt,NetSys/quilt,quilt/quilt,quilt/quilt,LuiseV/quilt,NetSys/quilt,LuiseV/quilt,quilt/quilt,NetSys/quilt,kelda/kelda,quilt/quilt,NetSys/quilt,kelda/kelda,NetSys/quilt