This method was added as part of a refactor in [moby@1ba1138], at which
time it was used to delete original values for "--host" and "--volume"
after normalizing. This beccame redundant in [moby@6200002], which added
specialized options that used a validate function, which both validated
and normalized inputs.
It's no longer used, so let's mark it deprecated so that we can remove it.
[moby@1ba1138]: 1ba11384bf
[moby@6200002]: 6200002669
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
193db8ec41