Fix built-in PNG library build with MSVC 9 and older

Upgrade the submodule to a version which doesn't try to use SSE2 with
this old compiler, as it doesn't support the required intrinsics.

See https://github.com/wxWidgets/libpng/pull/4
This commit is contained in:
Vadim Zeitlin
2020-04-24 00:42:41 +02:00
parent 4ee7202121
commit dc34600c0c

Submodule src/png updated: 8cb5f8f158...f1ecc2c50d