Update the reason why USE=spice is masked for app-emulation/qemu. I
can't find the original underlying announcement where they explained why
it was disabled but this is better than nothing.
Gentoo-Bug: 576944
# Doug Goldstein <cardoe@gentoo.org> (17 Jan 2012)
# The SPICE server is only supported on 64-bit platforms and not on 32-bit
+# https://lists.freedesktop.org/archives/spice-devel/2015-September/021846.html
app-emulation/qemu spice
# Alexandre Rostovtsev <tetromino@gentoo.org> (09 Jan 2012)