package/jack2: bump to version 1.9.17

package/jack2: bump to version 1.9.17

- Add COPYING as a license files, available since version 1.9.15 and
  https://github.com/jackaudio/jack2/commit/d75ddb82304bf500b031f52c11b0a106e2dc9a55
- Update indentation in hash file (two spaces)

https://github.com/jackaudio/jack2/releases/tag/v1.9.15
https://github.com/jackaudio/jack2/releases/tag/v1.9.16
https://github.com/jackaudio/jack2/releases/tag/v1.9.17

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>