Changed wxImage.ResampleBox to always use a box size of at least 2 by 2 pixels.

Changed wxImage.ResampleBox to always use a box size of at least 2 by 2 pixels.

Previously when resizing by more than 50% (for example resizing from 100x100 to 51x51 or 140x140) a box size of 1x1 would be used which effectively would give the same result as using nearest neighbour. Make sure that at least a box size of 2x2 pixels is always used.

Patch by scottb, see also #12845.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@67202 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775