spice.proto: add SPICE_MSG_LIST to base channel
spice.proto: add SPICE_MSG_LIST to base channel

SPICE/spice-protocol,vdiot/spice-protocol,vdiot/spice-protocol,fgouget/spice-protocol,vdiot/spice-protocol,fgouget/spice-protocol,SPICE/spice-protocol,fgouget/spice-protocol,SPICE/spice-protocol