I didn't realize the `git.subprocess=false`
deprecation was coming -this- soon, or I'd have
started warning in 0.28.0 and dropped the USE
default in 0.29.0.
Instead, I'm leaving it default and warning, and
it'll be removed entirely next update.
Signed-off-by: Vivian Heisz (demize) <demize@unstable.systems>
