[Committer needed] devel/gitg: update to 3.26.0

[Hiroki Tagato]

Hi ports committers,

Could somebody take care of the following PR?

Bug 221783 - [PATCH]devel/gitg: update from 3.24.0 to 3.26.0
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=221783

The PR unbreaks devel/gitg and update it to 3.26.0.

The maintainer hasn't responded for over a month and I would consider 
that as a maintainer timeout.

Thanks,
Hiroki Tagato