vm/qubes_netwatcher: correct type in service name (#465)

This prevented netwatcher being started in the firewallvm.

network/qubes_netwatcher

@@ -18,8 +18,8 @@ while true; do
 		# thus, no sanitization ready
 		# but be careful when passing it to other shell scripts
 		if [[ "$UNTRUSTED_NETCFG" != "$CURR_NETCFG" ]]; then
-			/sbin/service qubes_firewall stop
-			/sbin/service qubes_firewall start
+			/sbin/service qubes-firewall stop
+			/sbin/service qubes-firewall start
 			CURR_NETCFG="$UNTRUSTED_NETCFG"
 			/usr/bin/xenstore-write qubes_netvm_external_ip "$CURR_NETCFG"
 		fi