advice: fix an unexpected leading space

advice: fix an unexpected leading space

This space was introduced, presumably unintentionally, in b3b18d1621
(advice: revamp advise API, 2020-03-02)

I notice this space due to confuse diff outputs while doing some
changes to enum advice_type.

As a reference, a recent change we have to that enum is:

    $ git show 35f0383

    ...
    diff --git a/advice.h b/advice.h
    index 0f584163f5..2affbe1426 100644
    --- a/advice.h
    +++ b/advice.h
    @@ -49,6 +49,7 @@ struct string_list;
	    ADVICE_UPDATE_SPARSE_PATH,
	    ADVICE_WAITING_FOR_EDITOR,
	    ADVICE_SKIPPED_CHERRY_PICKS,
    +       ADVICE_WORKTREE_ADD_ORPHAN,
     };

Note the hunk header, instead of a much more expected:

    @@ -49,6 +49,7 @@ enum advice_type

Signed-off-by: Rubén Justo <rjusto@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>