resolve an issue in the developing-load-manager doc
### Motivation
Resolves an issue in the load-manager docs
### Modifications
added "broker" in the shell command for updating loadManagerClassName so that it works.
@@ -15,7 +15,7 @@ There are two ways that you can enable the modular load manager:
2. Using the `pulsar-admin` tool. Here's an example:
```shell
- $ pulsar-admin update-dynamic-config \
+ $ pulsar-admin brokers update-dynamic-config \
--config loadManagerClassName \
--value org.apache.pulsar.broker.loadbalance.impl.ModularLoadManagerImpl
```
