proto: Remove deprecated drift_threshold_millis
The field is removed as it was deprecated in 8f9dd5ab (proto: Introduce drift_threshold to replace drift_threshold_millis, 2022-08-05) and not used anymore.
Closes: #4417 (closed)
The field is removed as it was deprecated in 8f9dd5ab (proto: Introduce drift_threshold to replace drift_threshold_millis, 2022-08-05) and not used anymore.
Closes: #4417 (closed)