Bug 7247 - rebuild_zebra.pl -v should show all Zebra log output

Bug 7247 - rebuild_zebra.pl -v should show all Zebra log output

Currently, -v option resets Zebra log output to default system values.

This produce amount of log specified in system defaults which is usually
too low for debugging.

This change explicitly forces all Zebra log output which create much more
chatter so it triggers with verbosity level 2

Test scenario:
1. pick koha site to reindex
2. use -v -v options to rebuild_zebra.pl to see additional output

Signed-off-by: Liz Rea <wizzyrea@gmail.com>
Verified help corrections and  loglevel 2 output vs. loglevel 1 output. No issues found.

Signed-off-by: Paul Poulain <paul.poulain@biblibre.com>