Mumble migrated from sourceforge to github. They also host their own homepage now. Therefore I think it's sensible to change the homepage in the builds from http://mumble.sourceforge.net/ to http://mumble.info/
commit 7aaa690d3c6c2367188eb2415637d12433f3b559 Author: Lars Wendler <polynomial-c@gentoo.org> Date: Wed Jan 18 17:50:57 2017 media-sound/murmur: Fixed HOMEPAGE variable (bug #606376). Package-Manager: Portage-2.3.3, Repoman-2.3.1 commit f13c5c8d578d71de08d6df8062f803623526af25 Author: Lars Wendler <polynomial-c@gentoo.org> Date: Wed Jan 18 17:26:39 2017 media-sound/mumble: Fixed HOMEPAGE variable (bug #606376). Package-Manager: Portage-2.3.3, Repoman-2.3.1