In "topup" mode, concurrent inserts make the row count unreliable

modules/Bio/EnsEMBL/Hive/RunnableDB/MySQLTransfer.pm

@@ -143,8 +143,8 @@ sub write_output {
         my $dest_row_increase = $self->get_row_count($dest_dbc, $table) - $self->param('dest_before_all');
 
         if($mode eq 'topup') {
-            if($src_before == $dest_row_increase) {
-                $self->warning("Successfully added $src_before '$table' rows");
+            if($src_before < $dest_row_increase) {
+                $self->warning("Cannot check success/failure in this mode, but the number of '$table' rows in target increased by $dest_row_increase (higher than $src_before)");
             } else {
                 die "Could not add rows: $src_before '$table' rows from source copied into $dest_row_increase rows in target\n";
             }