Upgrade libpng to 1.2.44 for security fixes.

Change-Id: Iae257ca6ea7031a99f38e9de196d71ef8b94f9aa
diff --git a/scripts/makefile.vcwin32 b/scripts/makefile.vcwin32
index 8cd806a..3cdfb39 100644
--- a/scripts/makefile.vcwin32
+++ b/scripts/makefile.vcwin32
@@ -1,11 +1,11 @@
 # makefile for libpng
 # Copyright (C) 1998 Tim Wegner
 # Copyright (C) 2006,2009 Glenn Randers-Pehrson
-
+#
 # This code is released under the libpng license.
 # For conditions of distribution and use, see the disclaimer
 # and license in png.h
-
+#
 # Assumes that zlib.lib, zconf.h, and zlib.h have been copied to ..\zlib
 # To use, do "nmake /f scripts\makefile.vcwin32"