Log Message:
Update to 3.17.6, to fix build with latest py-sip.

Changes:
PyQt v3.17.6 has been released. This fixes a Windows compilation bug.

PyQt v3.17.5 has been released. This is mainly to be compatible
with SIP v4.7.8 but also adds a couple of new methods.

    * Added the missing QRegion.rects() (based on a patch from
    Hans-Peter Jansen).
    * Added the missing QWidget.stackUnder() slot.