Fix wxPropertyGrid::GetPropertyRect when the last item is collapsed.

Return the real height instead of -1.

Closes #15367.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@74627 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/propgrid/property.cpp

@@ -2198,7 +2198,7 @@ int wxPGProperty::GetY2( int lh ) const
     for ( parent = GetParent(); parent != NULL; parent = child->GetParent() )
     {
         if ( !parent->IsExpanded() )
-            return -1;
+            return parent->GetY2(lh);
         y += parent->GetChildrenHeight(lh, child->GetIndexInParent());
         y += lh;
         child = parent;