build-sys: bump to spice-protocol 0.12.11
build-sys: bump to spice-protocol 0.12.11

Needed for GL messages

Signed-off-by: Marc-André Lureau <a6f2b960a4aca61381fc650a67901b2ac8e83e6d@gmail.com>

SPICE/spice-gtk,SPICE/spice-gtk,fgouget/spice-gtk,fgouget/spice-gtk,flexVDI/spice-gtk,fgouget/spice-gtk,flexVDI/spice-gtk,SPICE/spice-gtk,SPICE/spice-gtk