...which apparently wants to internally call some operator<< for Polygon
(rPolyPoly.GetObject(i)), but which doesn't exist (and appears to not have
existed when this operator<< for PolyPolygon was added with
e4be770e "add std::ostream operators for Region
and PolyPolygon"), so uses the non-explicit PolyPolygon ctor that takes a
Polygon, and causes infinite recursion for any non-empty PolyPolygon

Change-Id: I308527dcfed18763c8c3ebbce823eea9a0340e70
Reviewed-on: https://gerrit.libreoffice.org/73388
Tested-by: Jenkins
Reviewed-by: Michael Stahl <Michael.Stahl@cib.de>