Bass PODxt: EQ 1 & 6 not precise

[arteme]

There is the following comment about eq_1_freq and eq_6_freq in mod-bassxt/src/config.rs:

// TODO: better (more?) points needed. this is often 1Hz off from what L6E shows :(
//       Maybe the string formatter used does incorrect rounding?

Indeed, pod-ui doesn't always match L6E: