Allow for old settings that have no iketype

This bit of code looks like it could do with the same test as https://github.com/pfsense/pfsense/pull/1412
This is executed when the "Connect" button is pressed from Status->IPsec
Somebody with these problematic old IPsec entries could test this - with current code I suspect that disconnect followed by connect - it will not connect. With this change it will (might?) connect again.