... and the cell didn't have a number format applied already,
[HH]:MM:SS instead of wall clock time format HH:MM:SS which comes
to a surprise anyway if the result is >=24h.

Related to tdf#125099

Change-Id: I6c19a86177f8714ac588d6798acf86e247a79b26
Reviewed-on: https://gerrit.libreoffice.org/72131Reviewed-by: Eike Rathke <erack@redhat.com>
Tested-by: Jenkins