package/exiv2: fix CVE-2019-17402

Exiv2 0.27.2 allows attackers to trigger a crash in Exiv2::getULong in
types.cpp when called from Exiv2::Internal::CiffDirectory::readDirectory
in crwimage_int.cpp, because there is no validation of the relationship
of the total size to the offset and size.

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>