This update for pngcheck fixes the following issues:

version update to 3.0.3 [boo#1202662]

* fixed a crash bug (and probable vulnerability) in large (MNG) LOOP chunks
* fixed a divide-by-zero crash bug (and probable vulnerability)
  in interlaced images with extra compressed data beyond the
  nominal end of the image data (found by "chiba of topsec alpha
  lab")

version update to 3.0.0

  * tweaked color definitions slightly to work better on terminals with white/light backgrounds
  * fixed DHDR (pre-MNG-1.0) bug identified by Winfried <szukw000@arcor.de>
  * added eXIf support (GRR: added check for II/MM/unknown format)
  * converted static const help/usage-related strings to macros so -Werror=format-security doesn't trigger (Ben Beasley)
  * added (help2man-generated) man pages for all three utils added top-level LICENSE file; fixed various compiler warnings
  * fixed buffer-overflow vulnerability discovered by "giantbranch of NSFOCUS Security Team" *               https://bugzilla.redhat.com/show_bug.cgi?id=1897485
  * found and fixed four additional vulnerabilities (null-pointer dereference and three buffer overruns)
  * an off-by-one bug in check_magic() (Lucy Phipps)
  * converted two zlib-version warnings/errors to go to stderr (Lemures Lemniscati, actually from 20180318; forwarded by LP)
  * fixed another buffer-overflow vulnerability discovered by "giantbranch of NSFOCUS Security Team" https://bugzilla.redhat.com/show_bug.cgi?id=1905775
  * removed -f ("force") option due to multiple security issues