Being in the project's top directory when starting or continuing a rebase
is not necessary since 533b703 (Allow whole-tree operations to be started
from a subdirectory, 2007-01-12).
Signed-off-by: SZEDER Gábor <szeder@ira.uka.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>