widget: Set cursor during construction
widget: Set cursor during construction

In a multimonitor environment can easily happen that a cursor is set
before some of the SpiceDisplays are created. IOW the first created
SpiceDisplay has the cursor but others don't.

To avoid the issue set the initial cursor using the "cursor" property
of the SpiceCursorChannel.

Resolves:
https://bugzilla.redhat.com/show_bug.cgi?id=1411380
Acked-by: Victor Toso <39b7599ff73bbf5db531748ba5250f21fa7120ff@redhat.com>

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