net/gerbera: Update to 1.9.1

Update maintainer entry
Partially backport upstream commit to fix compilation when libinotify is
used

Changelog: https://github.com/gerbera/gerbera/releases/tag/v1.9.1
Reference: https://github.com/gerbera/gerbera/commit/3a29599b8ca82c0cf59392fc1495d32c88580a18

Approved by: tcberner (mentor)
Differential Revision: https://reviews.freebsd.org/D31735