package/jpeg-turbo: security bump to version 2.0.5

package/jpeg-turbo: security bump to version 2.0.5

Fixes the following security issue:

- CVE-2020-13790: ibjpeg-turbo 2.0.4, and mozjpeg 4.0.0, has a heap-based
  buffer over-read in get_rgb_row() in rdppm.c via a malformed PPM input
  file

For more details, see the release notes:
https://github.com/libjpeg-turbo/libjpeg-turbo/releases/tag/2.0.5

Signed-off-by: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
[Peter: mark as security bump / extend commit message]
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>