worker: Remove duplicate DISPLAY_CLIENT_TIMEOUT define
worker: Remove duplicate DISPLAY_CLIENT_TIMEOUT define

Acked-by: Fabiano Fidêncio <2931bae082ef9bc04523ba759c03a4778316d48f@redhat.com>

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