Bug 19190: Silly calculation of average time in touch_all scripts

Bug 19190: Silly calculation of average time in touch_all scripts

When you want to calculate average time, do not divide count by time :)

Test plan:
Run the script with a where condition and verbose option and see that
the average time is meaningful.

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: David Bourgault <david.bourgault@inlibro.com>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>