[Service Bus] Fix DEBUG variable (Azure#13348)

Author: HarshaNalluru

sdk/servicebus/service-bus/README.md

@@ -391,7 +391,7 @@ export DEBUG=azure*,rhea*,-rhea:raw,-rhea:message,-azure:core-amqp:datatransform
 - If you are interested only in **errors**, then you can set the `DEBUG` environment variable as follows:
 
 ```bash
-export DEBUG=azure:service-bus:error,azure-core-amqp:error,rhea-promise:error,rhea:events,rhea:frames,rhea:io,rhea:flow
+export DEBUG=azure:service-bus:error,azure:core-amqp:error,rhea-promise:error,rhea:events,rhea:frames,rhea:io,rhea:flow
 ```
 
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