FIX index in dematpayslip archive table

lib/Migration/Version030102Date20210812020000.php

@@ -31,7 +31,7 @@ class Version030102Date20210812020000 extends SimpleMigrationStep {
 
         $table = $schema->getTable('dematpayslip_archive');
 
-        $table->dropIndex('dematpayslip_archive_id_file');
+        //$table->dropIndex('dematpayslip_archive_id_file');
         $table->addIndex(['id_file'], 'demat_archive_id_file');
 
         return $schema;