global_return_routes fix

[5andr0]

Hey @dperson, long time no see!
i started using your docker hub image and found out that my global return routes aren't working anymore.

ip -4 route | grep -q "$i\\>" || 
    ip route add default via $g table 10

the route on table 10 wasn't added because it falsely detected the default gateway route as a duplicate.
To check if the table 10 entries already exists you have to add show table 10 on the ip commands like in my fix here.

You also had a copy paste error. You referenced $i instead of $g in the for g in $gw loops.

This will fix #316 and all other remote port issues

Let me know when the fix is on docker hub

Cheers!

[javierdlg]

Looks like this recent merge keeps old routing preferences if they get changed through the docker compose yaml. See #342 for where I'm hitting this issue when I changed networks and changed the routing. The old entry gets pulled from somewhere but I can't tell where and it kills my vpn's network