build-sys: Update keycodemapdb submodule
build-sys: Update keycodemapdb submodule

This brings in 2 bug fixes, one of these is important on RHEL7 to
workaround an argparser bug with the python2 version it ships.

Signed-off-by: Christophe Fergeau <05b95054a663c388a4e33d95828cb30f0370f8ef@redhat.com>

flexVDI/spice-gtk,flexVDI/spice-gtk