Update Vagrant configuration for Buster

This commit ensures that gvaweb can be installed in a Debian Buster
libvirt Vagrant box. The changes have previously been explored by
changing the Vagrant configuration for gvaldap.

change-vmdebootstrap-default-dhcp.sh

@@ -0,0 +1,15 @@
+#!/bin/sh
+
+set -e
+
+debootstrap_network=/etc/systemd/network/99-dhcp.network
+
+if grep -q '^Name=\\*' "${debootstrap_network}"; then
+  primary_nic=$(ls -1 /sys/class/net | grep -v lo |sort | head -1)
+  sed -i "s/^Name=e\\*/Name=${primary_nic}/" \
+    "${debootstrap_network}"
+  systemctl restart systemd-networkd.service
+  echo "Changed systemd network configuration"
+else
+  echo "Systemd network configuration has already been changed"
+fi