[fix] Only decompress the payload if it's not empty

[stepanbujnak]

Motivation

The message payload is optional and in some cases only message properties are sent. In this case, the message decompression would fail.

Modifications

Only do the decompression if the payload is not empty.

Verifying this change

• Make sure that the change passes the CI checks.

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

Does this pull request potentially affect one of the following parts:

If yes was chosen, please highlight the changes

• Dependencies (does it add or upgrade a dependency): no
• The public API: no
• The schema: no
• The default values of configurations: no
• The wire protocol: no

Documentation

• Does this pull request introduce a new feature? no
• If yes, how is the feature documented? not applicable
• If a feature is not applicable for documentation, explain why? it's just a bugfix
• If a feature is not documented yet in this PR, please create a followup issue for adding the documentation

[crossoverJie]

LGTM