Bug#1000805: /usr/bin/cjpeg: cjpeg with pgm generates 3 components jpeg file

[Mathieu Malaterre]

Control: tags -1 confirmed upstream fixed-upstream patch

See:

* 
https://github.com/libjpeg-turbo/libjpeg-turbo/commit/2ce32e0fe53fb402c78c92137998c5119d09aee0.patch