fix Validators unit test

Author: mawen12

client/src/test/java/org/apache/rocketmq/client/ValidatorsTest.java

@@ -22,6 +22,7 @@
 import org.apache.rocketmq.client.exception.MQClientException;
 import org.apache.rocketmq.common.TopicConfig;
 import org.apache.rocketmq.common.constant.PermName;
+import org.apache.rocketmq.common.help.FAQUrl;
 import org.apache.rocketmq.common.topic.TopicValidator;
 import org.apache.rocketmq.remoting.protocol.ResponseCode;
 import org.junit.Test;
@@ -38,7 +39,7 @@ public void testGroupNameBlank() {
             Validators.checkGroup(null);
             fail("excepted MQClientException for group name is blank");
         } catch (MQClientException e) {
-            assertThat(e.getErrorMessage()).isEqualTo("the specified group is blank");
+            assertThat(e.getErrorMessage()).isEqualTo("the specified group is blank" + FAQUrl.suggestTodo(FAQUrl.CLIENT_PARAMETER_CHECK_URL));
         }
     }