Fix ipa-server-install in pure IPv6 environment
Installation in pure IPv6 environment failed because pki-tomcat tried to use
IPv4 loopback. Configuring tomcat to use IPv6 loopback instead of IPv4 fixes
this issue.
https://fedorahosted.org/freeipa/ticket/4291
Reviewed-By: Martin Basti <mbasti@redhat.com>