base-files: Increase failsafe trigger wait time from 2 to 4 sec

base-files: Increase failsafe trigger wait time from 2 to 4 sec

Increase the failsafe waiting timeout period from 2 seconds
to 4 seconds.

Since commit 29207748b in 2015 we have had a rapid LED blinking
indication for the failsafe triggering period. But the really short
timeout of 2 seconds requires snappy reaction time from the user to
notice the LED blinking and to push button inside the short window.

Relax the timeout to 4 seconds, which more easily allows to notice
the change in LED blinking and push a button.

Signed-off-by: Hannu Nyman <hannu.nyman@iki.fi>
Link: https://github.com/openwrt/openwrt/pull/11852
Signed-off-by: Robert Marko <robimarko@gmail.com>