Change _lp_hostname() to return 2 when disabled
Change _lp_hostname() to return 2 when disabled

Technically there is no _ENABLE_ option for hostname, but there is
LP_HOSTNAME_ALWAYS, and when it is "-1" the hostname is effectivly
disabled. This return code can make it more clear that there is a
difference between no need for a hostname and when the user never wants
one.

nojhan/liquidprompt,pkkolos/liquidprompt,jaesivsm/liquidprompt,laurentbardin/liquidprompt,milouse/liquidprompt