After switching to use the tempfile module in commit 9e903316
(credential-cache--daemon: use tempfile module), no declarations from
sigchain.h are used in credential-cache--daemon.c anymore. Thus, remove
the #include.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: Junio C Hamano <gitster@pobox.com>