index: --compact respects --jobs

And -compact supports --jobs=0 like -index to disable parallel
execution.  Running three xapian-compact processes in parallel
on a USB 2.0 HDD is pretty painful.

1 files changed, 1 insertions, 1 deletions

diff --git a/lib/PublicInbox/Xapcmd.pm b/lib/PublicInbox/Xapcmd.pm
index d6c069d7..3b7a581b 100644
--- a/lib/PublicInbox/Xapcmd.pm
+++ b/lib/PublicInbox/Xapcmd.pm
@@ -129,7 +129,7 @@ sub same_fs_or_die ($$) {
 
 sub process_queue {
         my ($queue, $cb, $opt) = @_;
-        my $max = $opt->{jobs} || scalar(@$queue);
+        my $max = $opt->{jobs} // scalar(@$queue);
         if ($max <= 1) {
                 while (defined(my $args = shift @$queue)) {
                         $cb->($args, $opt);