Bug 20745: koha-zebra doesn't return the correct error codes

Bug 20745: koha-zebra doesn't return the correct error codes

This patch makes koha-zebra return 0 (or 1) even when verbose mode is
off. This made koha-zebra --start always return a failure even when the
daemon was correctly launched.

To test:
- Have Zebra running for kohadev instance on your KohaDevBox
- Run:
  $ sudo koha-zebra --stop kohadev && echo yay || echo doh
=> FAIL: 'doh' is printed
- Run:
  $ sudo koha-zebra --start kohadev e&& echo yay || echo doh
=> FAIL: 'doh' is printed as well
- Apply this patch
- Run:
  $ sudo perl misc4dev/cp_debian_files.pl
  $ sudo koha-zebra --stop kohadev && echo yay || echo doh
=> SUCCESS: 'yay' is printed
- Run:
  $ sudo koha-zebra --start kohadev e&& echo yay || echo doh
=> SUCCESS: 'yay' is printed
- Sign off :-D

Sponsored-by: ByWater Solutions
Signed-off-by: Mark Tompsett <mtompset@hotmail.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>