TLS disable ECDSA for MQTT to ensure we don't break fingerprints after #22649

[s-hadinger]

Description:

Since #22649 ECDSA is also accepted. There is however an edge case where the server could prefer ECDSA to RSA, and would break the fingerprint authentication. For now, we will force MQTT to use RSA only. Webclient would be allowed to use ECDSA and RSA.

Checklist:

• The pull request is done against the latest development branch
• Only relevant files were touched
• Only one feature/fix was added per PR and the code change compiles without warnings
• The code change is tested and works with Tasmota core ESP8266 V.2.7.8
• The code change is tested and works with Tasmota core ESP32 V.3.1.0.241206
• I accept the CLA.

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