PubSubClient (ThingsBoard)

What's Changed

• Update library properties by @damdo in #6
• fix progmem access crash by @hmueller01 in #5
• fix: keepalive behviour when set to 0 by @damdo in #7
• Integrate fixes for thingsboard/thingsboard-client-sdk#202 by @MathewHDYT in #9

New Contributors

• @damdo made their first contribution in #6
• @hmueller01 made their first contribution in #5

Full Changelog: v2.9.3...v2.9.4