Avoid NPE in MultiNodePipelineBase.java

should get connection first and then create new pipeline queue, otherwise it would cause NPE when timeout for getting connection and call sync() method

src/main/java/redis/clients/jedis/MultiNodePipelineBase.java

@@ -63,16 +63,16 @@ protected final <T> Response<T> appendCommand(CommandObject<T> commandObject) {
       queue = pipelinedResponses.get(nodeKey);
       connection = connections.get(nodeKey);
     } else {
-      pipelinedResponses.putIfAbsent(nodeKey, new LinkedList<>());
-      queue = pipelinedResponses.get(nodeKey);
-
       Connection newOne = getConnection(nodeKey);
       connections.putIfAbsent(nodeKey, newOne);
       connection = connections.get(nodeKey);
       if (connection != newOne) {
         log.debug("Duplicate connection to {}, closing it.", nodeKey);
         IOUtils.closeQuietly(newOne);
       }
+
+      pipelinedResponses.putIfAbsent(nodeKey, new LinkedList<>());
+      queue = pipelinedResponses.get(nodeKey);
     }
 
     connection.sendCommand(commandObject.getArguments());