[PATCH] gateway: Fix typo when setting 'is_vpn6'

Hi,  

I was testing connman's wireguard plugin and got a segmentation fault.

Looking at the backtrace revealed that there are some typos in the `src/gateway.c` file where `is_vpn6` was incorrectly set using ipv4 variables instead of ipv6 regarding vpn.

I simply changed them to ipv6 and got it working.

not related to the patch:
I had to manually add ip route so the other devices could be pinged
The plugin adds routes for the WireGuard.DNS configuration setting
# ip route
1.1.1.1 dev wg0 scope link 
8.8.8.8 dev wg0 scope link 
10.42.0.0/24 dev end1 proto kernel scope link src 10.42.0.83 
10.42.0.1 dev end1 scope link 
<vpn host ip> via 10.42.0.1 dev end1

the missing route added manually:
ip route add 10.33.0.0/16 dev wg0 scope link

an equivalent wireguard file adds it properly (using wg-quick)

Is the plugin lacking some implementation?

---
 src/gateway.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/gateway.c b/src/gateway.c
index 16c87f83..b2c211e2 100644
--- a/src/gateway.c
+++ b/src/gateway.c
@@ -3704,10 +3704,10 @@ int __connman_gateway_add(struct connman_service *service,
 					is_gateway_config_vpn(
 						new_gateway->ipv4_config);
 
-		is_vpn6 = do_ipv4 &&
-					new_gateway->ipv4_config &&
+		is_vpn6 = do_ipv6 &&
+					new_gateway->ipv6_config &&
 					is_gateway_config_vpn(
-						new_gateway->ipv4_config);
+						new_gateway->ipv6_config);
 
 	} else {
 		if (do_ipv4 && new_gateway->ipv4_config)
-- 
2.43.0