IPVanish and OVPN maintenance

What's Changed

• Change IPVanish OpenVPN config base URL to version v2.6.0-0 per issue #3012 by @BillyAlt in #3026
• Clarify OPENVPN_CONFIG variable description by @schmamps in #2988
• Remove OVPN bundled configure-openvpn.sh in favor of external contrib by @haugene in #3034
• Fix IPVanish script by @haugene in #3035

New Contributors

• @BillyAlt made their first contribution in #3026
• @schmamps made their first contribution in #2988

Full Changelog: v5.5.0...v5.5.1