Bug 15014: Returns 0 if everything went fine

Be kind and return 0 if the sample file has been generated correctly.
Otherwise you are a bad guy and you make Plack returns an internal error
(exited nonzero: 1 at /home/vagrant/kohaclone/tools/import_borrowers.pl line 390.)

Signed-off-by: Josef Moravec <josef.moravec@gmail.com>
Works as expected
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Works as expected here too.

(cherry picked from commit 314f3e22d9)
Signed-off-by: Frédéric Demians <f.demians@tamil.fr>

tools/import_borrowers.pl

@@ -97,7 +97,7 @@ if ($input->param('sample')) {
     );
     $csv->combine(@columnkeys);
     print $csv->string, "\n";
-    exit 1;
+    exit 0;
 }
 my $uploadborrowers = $input->param('uploadborrowers');
 my $matchpoint      = $input->param('matchpoint');