```
alter routine load for cmy2 from kafka("kafka_broker_list" = "ip2:9094", "kafka_topic" = "my_topic");
```
This is useful when the kafka broker list or topic has been changed.
Also modify `show create routine load`, support showing "kafka_partitions" and "kafka_offsets".
Support ALTER ROUTINE LOAD JOB stmt, for example:
```
alter routine load db1.label1
properties
(
"desired_concurrent_number"="3",
"max_batch_interval" = "5",
"max_batch_rows" = "300000",
"max_batch_size" = "209715200",
"strict_mode" = "false",
"timezone" = "+08:00"
)
```
Details can be found in `alter-routine-load.md`
