When dupe-finder was switched from ->search->{over_ro} to ->over, the
database handle was dropped. Restore it because a spot downstream
uses it.
Fixes: 73e3a6ed6e95adc6 (use more idiomatic internal API for ->over access)
(cherry picked from commit
0438ee2b1a5fbeb587ee62aa3e267ec09d281bd9)
$ibx or die "No inbox";
$ibx->search or die "search not available for inbox";
my $over = $ibx->over;
+my $dbh = $over->dbh;
sub emit ($) {
my ($nums) = @_;