fix classname flag in python function example
@@ -235,7 +235,7 @@ Here, the `process` method defines the processing logic of the Pulsar Function.
```bash
$ bin/pulsar-admin functions create \
--py reverse.py \
- --class-name reverse \
+ --classname reverse \
--inputs persistent://public/default/backwards \
--output persistent://public/default/forwards \
--tenant public \
