This reverts commit acd68a9a5d.
Reason for revert: Doesn't get values for non scoped config.
Original change's description:
> Avoid silently overwriting diff.ignoreSubmodules config.
>
> Setting this to `dirty` is generally desirable. If the user has
> explicitly set it to something else on their chromium checkout,
> warn rather than silently overwriting.
>
> Bug: 362787698
> Change-Id: I56587d501aafc5de78c82bc46e29f926519d25fa
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/5832742
> Reviewed-by: Josip Sokcevic <sokcevic@chromium.org>
> Commit-Queue: Helmut Januschka <helmut@januschka.com>
Bug: 362787698
Change-Id: I3e5d1e44e3707dda53dc398f83c43259868d343b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/5842067
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Reviewed-by: Joey Scarr <jsca@google.com>
Owners-Override: Joey Scarr <jsca@google.com>
Commit-Queue: Dan Le Febvre <dlf@google.com>
