x11/citron: update to 0.6.4

v0.6.4
-Hotfix: squash a bug that stopped network statistics from showing up on NetBSD.

v0.6.3
-This addresses a bug (incorrect filter usage) that occurs
during the fetching of battery statistics on Linux.

v0.6.2
-Small fix in the backend that adds back an allow:dead_code attribute in
a specific module to avoid getting a bunch of warnings at build-time.

v0.6.1
-citron is not affected by libmacchina's new breaking changes, but the most
notable change in this new version of libmacchina is the introduction
of the "hash" feature, which citron does not enable, this drops a lot of
dependencies that we don't need.

v0.6.0
-Add icon support

(pin)