server: Remove a redundant CursorChannelClient typedef
server: Remove a redundant CursorChannelClient typedef

CursorChannelClient is already defined in cursor-channel-client.h.
This fixes compilation errors with gcc 4.4.7 on RHEL 6.8.

Signed-off-by: Francois Gouget <6b915da68578f6eb004fe99432b967565fc9be8f@codeweavers.com>
Acked-by: Pavel Grunt <fbda40b445316123f12a5a6bd7556918ea74f4bc@redhat.com>

fgouget/spice,fgouget/spice,fgouget/spice,fgouget/spice