[improve][doc] Default behaviour with acknowledge timeout

[AlvaroStream]

For newcomers this is a question it can be important.

It is mentioned here

Motivation

The documentation was lacking this default as a note.

Modifications

Added the information in case somebody forgets to configure ackTimeOut.

Verifying this change

• [ X ] 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 the box was checked, please highlight the changes

• Dependencies (add or upgrade a dependency)
• The public API
• The schema
• The default values of configurations
• The threading model
• The binary protocol
• The REST endpoints
• The admin CLI options
• Anything that affects deployment

Documentation

• doc
• doc-required
• doc-not-needed
• doc-complete

Matching PR in forked repository

PR in forked repository: