Only restart network once

One restart of the network restart is needed to get Avahi DNS resolution
to work, however restarts on subsequent --refresh runs are wasting time.

Signed-off-by: Georg Pfuetzenreuter <mail@georg-pfuetzenreuter.net>

Vagrantfile-Template

@@ -14,7 +14,11 @@ Vagrant.configure("2") do |config|
   config.vm.box = ENV['SCULLERY_BOX_NAME']
   config.vm.box_url = ENV['SCULLERY_BOX_IMAGE']
   config.vm.provision "shell", inline: <<-SHELL
+  if [ ! -f '/var/adm/scullery.configured' ]
+  then
     systemctl restart network
+    touch /var/adm/scullery.configured
+  fi
   SHELL
   if ENV['SCULLERY_MASTERS']
     ENV['SCULLERY_MASTERS'].split(',').each do |vmname|