busybox: show reproducible timestamp
On login busybox shows a timestamp per default contianing the build
date. Since the build date isn't reproducible per default this behaviour
was disabled by default via
34df4d40 "busybox: disable timestamp in
version".
This commit modifies busybox so that the printed timestamp reproducible
using SOURCE_DATE_EPOCH and therefore shouldn't be disabled anymore.
Before:
BusyBox v1.33.1 () built-in shell (ash)
After:
BusyBox v1.33.1 (2021-05-13 09:34:34 UTC) built-in shell (ash)
Signed-off-by: Paul Spooren <mail@aparcar.org>