bugfix:  using subdomain of xip.io buggy
bugfix:  using subdomain of xip.io buggy

rs-cloud.xip.io initially behaved as expected,  but doesn't seem to anymore.

we should just use `#{public_ip_address}.xip.io`
vhl/knife-rackspace,chef/knife-rackspace,philoserf/knife-rackspace,rackspace/knife-rackspace,martinb3/knife-rackspace,srirajan/knife-rackspace,decklin/knife-rackspace,tdooner/knife-rackspace,chef/knife-rackspace