This simplifies rendering the hostname (or hostname+delegated host) in
the default callback module, and reduces code duplication
I've chosen not move where in each handler the host label is rendered,
in case subsequent operations has side effects. However I'm happy to
change that if considered safe.
I've chosen not to change the formatting operator used (%), to avoid
changes in rendering that might result.
Signed-off-by: Alex Willmer <alex@moreati.org.uk>
185d410316