spice: Remove unused include

The definitions in the header are not  used.
Also this fixes porting SPICE to Windows where the header is not
available.
Signed-off-by: NFrediano Ziglio <fziglio@redhat.com>
Reviewed-by: NPhilippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20190107184404.31993-1-fziglio@redhat.com
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>

ui/spice-core.c

@@ -18,7 +18,6 @@
 #include "qemu/osdep.h"
 #include <spice.h>
 
-#include <netdb.h>
 #include "sysemu/sysemu.h"
 
 #include "ui/qemu-spice.h"