openvpn: rework openvpn to work on newer Fedoras
- fix configuration to avoid rhbz1909741
- move certs to contrib/openvpn and alter paths
- move setup from tags.py to libs.py
- no need to down eth0 (use testeth10 instead)
- install openvpn/NetworkManager-openvpn in envsetup from epel only
- better cleanup (delete tun0)
Edited by Vladimír Beneš