C* Eq causes constant quiet noise

[noise.mmp.zip](https://github.com/LMMS/lmms/files/7271298/noise.mmp.zip)

In this project the effect is ridiculously amplified, the Eq by itself generates a continuous humming with an amplitude of only a single numeric value. The frequency of the noise changes with the sample rate so the waveform on the top display is always in perfect sync.
With the builtin multi-streamed instruments the humming starts only if you press a note.
The glitch is also present in the exported audio regardless of the format, it just gets buried in the 16 bit resolution if not amplified.

Tested in current master and 1.2.2 stable.

Open the attached noise.mmp project and reproduce the continuous hum with the C* Eq, including during playback and export at different sample rates. Compare the top display waveform and exported audio, and consider the issue resolved when the Eq no longer generates the amplified tone or leaves it in exported audio.

Written by the indexing model from the issue text.