Fix mqtt topic for dimmers

[effelle]

Description:

Fix topic regression for dimmers levels when value is set using phisical buttons/sliders.

Related issue (if applicable): fixes #9583

Checklist:

• The pull request is done against the latest dev branch
• Only relevant files were touched
• Only one feature/fix was added per PR.
• The code change is tested and works on Tasmota core ESP8266 V.2.7.4.5
• The code change is tested and works on core ESP32 V.1.12.2
• I accept the CLA.

NOTE: The code change must pass CI tests. Your PR cannot be merged unless tests pass

[cprussin]

Thank you!