fix #2531 check reindex status

src/main/java/org/codelibs/fess/app/web/admin/maintenance/AdminMaintenanceAction.java

@@ -309,9 +309,10 @@ public class AdminMaintenanceAction extends FessAdminAction {
         if (searchEngineClient.createIndex(docIndex, toIndex, numberOfShards, autoExpandReplicas, resetDictionaries)) {
             searchEngineClient.admin().cluster().prepareHealth(toIndex).setWaitForYellowStatus().execute(ActionListener.wrap(response -> {
                 searchEngineClient.addMapping(docIndex, "doc", toIndex);
-                searchEngineClient.reindex(fromIndex, toIndex, replaceAliases);
-                if (replaceAliases && !searchEngineClient.updateAlias(toIndex)) {
-                    logger.warn("Failed to update aliases for {} and {}", fromIndex, toIndex);
+                if (searchEngineClient.reindex(fromIndex, toIndex, replaceAliases)) {
+                    if (replaceAliases && !searchEngineClient.updateAlias(toIndex)) {
+                        logger.warn("Failed to update aliases for {} and {}", fromIndex, toIndex);
+                    }
                 }
             }, e -> logger.warn("Failed to reindex from {} to {}", fromIndex, toIndex, e)));
             return true;