Skip test_server_connectivity_cold_migration_revert until fixed

test_server_connectivity_cold_migration_revert has begun failing again
pretty consistently (though not 100%) as soon as we merged the match
to un-skip it. Start skipping it again until we work out the issues.

Change-Id: I9b4cf79d223cbb399b5857571114665cd03e8921
Related-Bug: #1836595
1 file changed