- Allow setting DHCP reservation preference with --unattended

- Flip condition check on $dhcpReserv: first check if empty, and if not, check if it's not 1.
  Doing it the other way (first check if not 1) would give a shell error if $dhcpReserv was empty.

auto_install/install.sh

@@ -166,7 +166,7 @@ main(){
 		avoidStaticIPv4Ubuntu
 	else
 		getStaticIPv4Settings
-		if [ "$dhcpReserv" -ne 1 ] || [ -z "$dhcpReserv" ]; then
+		if [ -z "$dhcpReserv" ] || [ "$dhcpReserv" -ne 1 ]; then
 			setStaticIPv4
 		fi
 	fi
@@ -596,6 +596,7 @@ getStaticIPv4Settings() {
 
 	if [ "${runUnattended}" = 'true' ]; then
 
+		if [ -z "$dhcpReserv" ] || [ "$dhcpReserv" -ne 1 ]; then
 			local INVALID_STATIC_IPV4_SETTINGS=0
 
 			if [ -z "$IPv4addr" ]; then
@@ -632,7 +633,11 @@ getStaticIPv4Settings() {
 					exit 1
 				fi
 			fi
+		else
+			echo "::: Skipping setting static IP address"
+		fi
 
+		echo "dhcpReserv=${dhcpReserv}" >> /tmp/setupVars.conf
 		echo "IPv4addr=${IPv4addr%/*}" >> /tmp/setupVars.conf
 		echo "IPv4gw=${IPv4gw}" >> /tmp/setupVars.conf
 		return