rdb adapter 增加 truncate dml适配 fixed #1408

fixed #1403

client-adapter/hbase/src/main/java/com/alibaba/otter/canal/client/adapter/hbase/HbaseAdapter.java

@@ -94,6 +94,9 @@ public class HbaseAdapter implements OuterAdapter {
     }
 
     public void sync(List<Dml> dmls) {
+        if (dmls == null || dmls.isEmpty()) {
+            return;
+        }
         for (Dml dml : dmls) {
             sync(dml);
         }