Abort if config cannot find viirb

viirb-2-configure-fully-after-upgrade.sh

@@ -31,6 +31,12 @@ public_key=$(echo $private_key | wg pubkey)
 vpn_endpoint_host=vpn-2a0ae5c1300.ungleich.ch
 vpn_endpoint_pubkey=ft68G2RID7gZ6PXjFCSCOdJ9yspRg+tUw0YrNK9cTxE=
 
+ping -c3 ${viirb_ip}
+if [ $? -ne 0 ]; then
+    echo "Cannot reach ${viirb_ip}, aborting"
+    exit 1
+fi
+
 cat <<EOF | ssh -t "root@${viirb_ip}"
 set -x
 # Setup lan to also retrieve an ip address via dhcp