Sanitize FQDN in config generator

Some projects (Ironic for example) may to use socket.getfqdn()
as default for 'host' config parameter. It can cause an error
in check_uptodate config test.

Closes-Bug: #1282481
Change-Id: I322b1f472babd3894a9a27269c03d5aace26d650
Merge "Sanitize FQDN in config generator"