package/docker-engine: bump to version 19.03.13

package/docker-engine: bump to version 19.03.13

The Docker developers appear to no longer be tagging releases on the
docker/engine repository on GitHub, but are tagging releases on the main
moby/moby repository, which still is the true home of "dockerd."

This commit changes the upstream repo to moby/moby with no changes required.

Signed-off-by: Christian Stewart <christian@paral.in>
v1 -> v2:

 - updated hash
 - changed upstream to moby/moby

Signed-off-by: Christian Stewart <christian@paral.in>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>