XCB: Drag and drop stops when window is minimized during dnd operation.

Drag and drop stops when window is minimized during dnd operation.

Steps to reproduce on KDE4:

• be sure that you have at least two virtual desktops (if you are using compositing, be sure that "Always (breaks minimization)" is NOT selected),
• open the application from attachment on virtual desktop 1,
• start drag (from applications window),
• now, you can drop it everywhere,
• change to the second desktop using keyboard (Ctrl+F2) (the windows is in minimized state now, see console output),
• now the dnd icon can't move, you can't drop the item,
• go back into first desktop (Ctrl+F1),
• now you can dnd only inside applications window, so you can't dnd into other application.

Works OK with Qt4.x.