Allow empty prefix for domain names
Allow empty prefix for domain names

Allows one to set a empty prefix for domain names
and it would create domain with the same name as set by define
method in the Vagrantfile.

Signed-off-by: raghavendra talur <155577b46ee1d37958061e87678ba3b3f3bcca42@gmail.com>

sendgrid-ops/vagrant-libvirt,pradels/vagrant-libvirt,leoh0/vagrant-libvirt,infernix/vagrant-libvirt,infernix/vagrant-libvirt,leoh0/vagrant-libvirt,skamithi/vagrant-libvirt,vagrant-libvirt/vagrant-libvirt,electrofelix/vagrant-libvirt,electrofelix/vagrant-libvirt,vagrant-libvirt/vagrant-libvirt,vagrant-libvirt/vagrant-libvirt,pradels/vagrant-libvirt,electrofelix/vagrant-libvirt,brk3/vagrant-libvirt,skamithi/vagrant-libvirt,sendgrid-ops/vagrant-libvirt,brk3/vagrant-libvirt,infernix/vagrant-libvirt