package/imagemagick: security bump to version 7.0.7-1

package/imagemagick: security bump to version 7.0.7-1

Quoting CVE-related issues from
https://github.com/ImageMagick/ImageMagick/blob/master/ChangeLog

2017-07-29 7.0.6-5 Glenn Randers-Pehrson <glennrp@image...>
  * Fix improper use of NULL in the JNG decoder (CVE-2017-11750, Reference
    https://github.com/ImageMagick/ImageMagick/issues/632).

2017-07-24 7.0.6-4 Cristy <quetzlzacatenango@image...>
  * Fixed numerous memory leaks (reference
    https://github.com/ImageMagick/ImageMagick/issues) including
    https://github.com/ImageMagick/ImageMagick/issues/618 (CVE-2017-12676).

2017-07-23  7.0.6-3 Glenn Randers-Pehrson <glennrp@image...>
  * Fix memory leaks when reading a malformed JNG image:
    https://github.com/ImageMagick/ImageMagick/issues/600 (CVE-2017-13141),
    https://github.com/ImageMagick/ImageMagick/issues/602 (CVE-2017-12565).

2017-07-19 7.0.6-2 Cristy <quetzlzacatenango@image...>
  * coders/png.c: fixed memory leak of quantum_info (CVE-2017-11539, reference
    https://github.com/ImageMagick/ImageMagick/issues/582
  * coders/png.c: fixed NULL dereference when trying to write an empty MNG
    (CVE-2017-11522, reference
    https://github.com/ImageMagick/ImageMagick/issues/586).

2017-06-22  7.0.6-1 Glenn Randers-Pehrson <glennrp@image...>
  * Stop a memory leak in read_user_chunk_callback() (reference
    https://github.com/ImageMagick/ImageMagick/issues/517,
    CVE 2017-11310).

Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>