Add soft-deletes to UNMODIFIABLE_SETTINGS when restore snapshot

Author: dnhatn

server/src/main/java/org/elasticsearch/snapshots/RestoreService.java

@@ -64,6 +64,7 @@
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.unit.TimeValue;
 import org.elasticsearch.index.Index;
+import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.index.shard.IndexShard;
 import org.elasticsearch.index.shard.ShardId;
 import org.elasticsearch.repositories.IndexId;
@@ -120,7 +121,8 @@ public class RestoreService extends AbstractComponent implements ClusterStateApp
             SETTING_NUMBER_OF_SHARDS,
             SETTING_VERSION_CREATED,
             SETTING_INDEX_UUID,
-            SETTING_CREATION_DATE));
+            SETTING_CREATION_DATE,
+            IndexSettings.INDEX_SOFT_DELETES_SETTING.getKey()));
 
     // It's OK to change some settings, but we shouldn't allow simply removing them
     private static final Set<String> UNREMOVABLE_SETTINGS;