Disable waveform while recording to reduce latency

[Trebor]

@diegotrex

Latency is a problem with my 11th Gen Intel(R) Core™ i7 ,with internal mic or external USB audio box, much much more than it was in 1997 ,with a Pentium 1 PC with few MB of RAM ,latency was apparently zero;

Audacity3 is much more CPU intensive than Audacity 1&2, because it has non-destructive editing, and Audcaity3, like Audacity 1&2, is only using 1 core