fix(YSP-593): do not overwrite old data each time

Marc has written about this, and it looks as if when an item is no
longer present in the payload that it gets wiped, which we do not want.

So we removed this; more testing needs to be done on the effects of
changing the data and how it updates.

web/profiles/custom/yalesites_profile/modules/custom/ys_servicenow/src/ServiceNowManager.php

@@ -150,11 +150,11 @@ public function runMigration($migration) {
 
       // We choose to use syncSource since we want to recreate the block for
       // update.
-      if ($migration === 'servicenow_knowledge_base_article_block') {
-        $migrationInstance->set('syncSource', TRUE);
-        $migration_update = $migrationInstance->getIdMap();
-        $migration_update->prepareUpdate();
-      }
+      /*if ($migration === 'servicenow_knowledge_base_article_block') {*/
+      /*  $migrationInstance->set('syncSource', TRUE);*/
+      /*  $migration_update = $migrationInstance->getIdMap();*/
+      /*  $migration_update->prepareUpdate();*/
+      /*}*/
       $message = new MigrateMessage();
       $executable = new MigrateExecutable($migrationInstance, $message);
       $executable->import();