As far I can see, this package is not proxy maintained. Please remove proxy-maint@gentoo.org
commit 14b69ef1c54cc5d0bf002ec47b0a1fec3911b49a (HEAD -> master, origin/master, origin/HEAD) Author: Lars Wendler <polynomial-c@gentoo.org> Date: Tue Jul 11 11:38:52 2017 net-misc/keychain: Removed proxy-maint team (bug #624538). Package-Manager: Portage-2.3.6, Repoman-2.3.2