common: Change daemon startup timeout from 5 to 8 seconds.

* common/asshelp.c (SECS_TO_WAIT_FOR_AGENT): Change from 5 to 8
seconds.
(SECS_TO_WAIT_FOR_KEYBOXD): Ditto.
(SECS_TO_WAIT_FOR_DIRMNGR): Ditto.

Experience on Windows showed that right after re-booting we may need
some more time to get things up.