Update security/olm to latest upstream release.
Source has moved to gitlab, still under Matrix.org. Release notes at
major changes were in 3.1.0 already, Short Authentication String
and public key signing. Various compatibility and build fixes
were also applied.
Also PORTREVISION dependent ports (that I know about). No MFH because
these are feature-based releases, not security updates.
Submitted by: Alexander Sieg
Reported by: Alexander Sieg