reduce test to valid argument

installers/common.sh

@@ -145,7 +145,7 @@ function configure_exit() {
 		sed -i 's#\#ifaddr=#ifaddr=172.16.0.1/16#g' /var/lib/lokinet/lokinet.ini
 		sed -i 's#\#paths=6#paths=8#g' /var/lib/lokinet/lokinet.ini
 		sed -i 's#\#net.ipv4.ip_forward=1#net.ipv4.ip_forward = 1#g' /etc/sysctl.conf
-		if [ -z $(grep "-A POSTROUTING -s 172.16.0.1/16 -o eth0 -j MASQUERADE" "/etc/iptables/rules.v4") ]; then iptables -t nat -A POSTROUTING -s 172.16.0.1/16 -o eth0 -j MASQUERADE; fi
+		if [ -z $(grep "172.16.0.1/16" "/etc/iptables/rules.v4") ]; then iptables -t nat -A POSTROUTING -s 172.16.0.1/16 -o eth0 -j MASQUERADE; fi
 #		iptables -t nat -A POSTROUTING -s 172.16.0.1/16 -o eth0 -j MASQUERADE
 		iptables-save > /etc/iptables/rules.v4
 		sudo sysctl -p /etc/sysctl.conf