Duplicate MQTT SUBSCRIBE for persistent sessions

[JuliusFruitfly]

Owntracks seems to re-issue subscriptions for a persistent mqtt session even when the protocol version is set to 4 (3.1.1) and the 'session present' flag is set in the CONNACK

This is a shame as it generates a lot of traffic on an unreliable connection

Thanks.

• App build number: 2.5.3 (420503003)
• Android version: 14
• Device: Xiaomi/Redmi Note 12
• Installation source: Google Play