Security update for jhead (moderate)

This update for jhead fixes the following issues:

Security issues fixed:

• CVE-2018-17088: The ProcessGpsInfo function may have allowed a remote
  attacker to cause a denial-of-service attack or unspecified other impact
  via a malicious JPEG file, because there is an integer overflow during a
  check for whether a location exceeds the EXIF data length. This is
  analogous to the CVE-2016-3822 integer overflow in exif.c. (boo#1108672)
• CVE-2018-16554: The ProcessGpsInfo function may have allowed a remote
  attacker to cause a denial-of-service attack or unspecified other impact
  via a malicious JPEG file, because of inconsistency between float and
  double in a sprintf format string during TAG_GPS_ALT handling.
  (boo#1108480)