Bump vendor/gitlab.com/openconnect/ocserv from a3ff686 to a711aa4

Bumps [vendor/gitlab.com/openconnect/ocserv](https://gitlab.com/openconnect/ocserv) from `a3ff686` to `a711aa4`.
- [Release notes](https://gitlab.com/openconnect/ocserv/tags)
- [Commits](https://gitlab.com/openconnect/ocserv/compare/a3ff6864b948f57b29033261e104db7e637bfda9...a711aa4a224ed3f6bf34e7bf0e91c7280226b2bf)

---
updated-dependencies:
- dependency-name: vendor/gitlab.com/openconnect/ocserv
  dependency-type: direct:production
...

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