BUG: Fix libpng warnings in console when loading images with Qt 4.8.7

This commit eliminates the following libpng warning seen when loading certain
PNG images using libpng 1.6.x, which is included in Qt 4.8.7:

libpng warning: iCCP: known incorrect sRGB profile

To fix the images I ran them through ImageMagick, which removes the incorrect
profiles, as suggested in [1]:

convert image.png image.png

libpng 1.6.17 describes the warning in png.c line 2308:

/* These profiles are known to have bad data that may cause
 * problems if they are used, therefore attempt to
 * discourage their use, skip the 'have_md5' warning below,
 * which is made irrelevant by this error.
 */

[1] http://stackoverflow.com/questions/22745076/libpng-warning-iccp-known-incorrect-srgb-profile

From: Max Smolens <max.smolens@kitware.com>

git-svn-id: http://svn.slicer.org/Slicer4/trunk@24571 3bd1e089-480b-0410-8dfb-8563597acbee