Update concepts-messaging.md (#3789)
Update concepts-messaging.md (#3789)

### Motivation

Documentation is inconsistency after the third compression was added. 

### Modifications

Update documentation text.

### Verifying this change

This change is a trivial rework / code cleanup without any test coverage.

massakam/pulsar,yahoo/pulsar,merlimat/pulsar,merlimat/pulsar,merlimat/pulsar,yahoo/pulsar,yahoo/pulsar,massakam/pulsar,yahoo/pulsar,massakam/pulsar,merlimat/pulsar,yahoo/pulsar,yahoo/pulsar,massakam/pulsar,merlimat/pulsar,merlimat/pulsar,massakam/pulsar,massakam/pulsar