Always grab the hostname from InetAddress.getLocalHost().getHostName()

The previous code would always trigger a reverse DNS lookup.  If the
workstation/server is not configured with a valid DNS name, the reverse
DNS lookup would timeout.  This would cause liquibase to hang for 10-15
seconds on some systems.
Merge pull request #207 from ibuildthecloud/fix-reverse-dns-hang

Always grab the hostname from InetAddress.getLocalHost().getHostName()