gc --auto --quiet: make the notice a bit less verboase
gc --auto --quiet: make the notice a bit less verboase

When "gc --auto --quiet" decides there is something to do, it tells the
user what it is doing, as it is going to make the user wait for a bit.

But the message was a bit too long.

Signed-off-by: Junio C Hamano <a6723cc3f76163bf7adb636a73ac3b0ceb3e6b9b@pobox.com>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git