Lift the default limit of number of revs.

Lift the default limit of number of revs.

Now that the leak is gone, there is by default no limit of revisions to
import.  No more message about leak when the limit (given by the -l
parameter) is reached.

Signed-off-by: Yaacov Akiba Slama <ya@slamail.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>