OpenVPN: Added correct index for ovpnconfig, modified legend in WUI

OpenVPN: Added correct index for ovpnconfig, modified legend in WUI

- Fix for #11048 which includes now an index parameter for 'pass' or 'no-pass' for all connections.
- Modification via update.sh to deliver an 'pass' (all crypted *.p12 files) or 'no-pass' (N2N and not encrypted files) index for all existing connections.
- Only one place for two different icons (encrypted or not encrypted) in HTML section in 'Connection Status and -Control'.
- Added new icon with already existing openvpn.png combined with an lock icon from https://www.freepik.com/ with the specific address https://www.flaticon.com/free-icon/lock_891399 which is free for personla and commercial use.
- Change 'Legend' order in 'Connection status and -Control' for better overview and change table width.
- Added new icon 'openvpn_encrypted.png' in 'Legend' section.

Signed-off-by: Erik Kapfer <erik.kapfer@ipfire.org>