[Conkeror] hints_auto_exit_delay default

[Silvio Levy]

I like the current default behavior a lot.  Jeremy's observations 
are right on target.  Very occasionally I mistype and don't hit the
backspace key in the 1-second window necessary to prevent a wrong link
from being followed.  Besides being rare, this event has always been
inconsequential for me.  By contrast, the time saved by not having to
type return to follow each link is considerable.

This said, so long as the current behavior is still supported somehow
(even if it's not the default), I'm happy.

Silvio