gitg now has a gsettings settings to disable/enable gravtar[0]. It is enabled by default. Can't Debian GNU/Linux include a patch that would disable gravtar by default?
I wish to have gitg 3.20 (preferably 3.22) in Debian Stretch GNU/Linux :) [0] https://mail.gnome.org/archives/commits-list/2015-July/msg06370.html