docker registry: Add error handling
docker registry: Add error handling

Some Docker::Images APIs do not raise exceptions on error
but put error records into the log.

This commit introduces log parsing and error extraction.

Signed-off-by: Dmitry Fleytman <a8cf97adadec4e1b734a39bc5aea71b5741cfca1@daynix.com>

daynix/rebuild,rbld/rebuild,rbld/rebuild,daynix/rebuild,daynix/rebuild,rbld/rebuild