Log Message:
Fix the gnome-screenshot application under NetBSD and close PR pkg/31936.
Bump PKGREVISION to 2.

NetBSD's poll(2) raises a POLLIN event when a file descriptor is closed;
Linux doesn't seem to do this.  This caused an unexpected G_IO_IN event
in gnome-screenshot's code that was used to detect errors, instead of the
G_IO_HUP it was expecting.