get a redis-cli image using docker pull

Signed-off-by: lixiaobing10051267 <li.xiaobing1@zte.com.cn>

docs/admin/ambassador_pattern_linking.md

@@ -70,7 +70,7 @@ On the Docker host (192.168.1.52) that Redis will run on:
     # start actual redis server
     $ docker run -d --name redis crosbymichael/redis
 
-    # get a redis-cli container for connection testing
+    # get a redis-cli image for connection testing
     $ docker pull relateiq/redis-cli
 
     # test the redis server by talking to it directly