remove the workaround for buggy recv_into()

[vladak]

The \x00 literal should be removed

Adafruit_CircuitPython_MiniMQTT/adafruit_minimqtt/adafruit_minimqtt.py

Line 984 in 342b8c9

if res in [None, b"", b"\x00"]:

once adafruit/circuitpython#7606 is fixed.

[vladak]

This should probably wait for some time for the CP versions with the fix to percolate to the wide public. This could take a long time, I think.

[brentru]

Both of these were added to CircuitPython as of 8.1.0 beta 1, let's keep this code in until 8.1.0 is stable and released.

[vladak]

8.1.0 has been stable as of last week it seems.