busybox: bump to version 1.24.0

Disable CONFIG_FEATURE_SYNC_FANCY in the busybox.config because that
option causes build failures for any uClibc based toolchains since it
requires syncfs() support, which doens't exist in uClibc.

This new option has been introduced in 1.24.0, so despite of disabling
it, we are not losing anything that we had before.

Signed-off-by: Vicente Olivert Riera <Vincent.Riera@imgtec.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>