Previously we only set the platform when performing a pull, which is
only initiated if pull always is set, or if the image reference does not
exist in the daemon.
The daemon now supports specifying which platform you wanted on
container create so it can validate the image reference is the platform
you thought you were getting.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
Commit 2b17f4c8a8 fixed the way empty labels
are taken into account (i.e. not interpolated from environment variable),
but it created a regression.
`ValidateLabel` functions doesn't allow empty label value, but it has
always been possible to pass an empty label via the cli (`docker run --label foo`).
This fixes that by not validating the label flag.
Signed-off-by: Vincent Demeester <vincent@sbr.pm>