Raise the default `synth.sample-rate` value to 48000

[fabiangreffrath]

I think any modern OS has gone the way from "CD quality" to "DVD quality" by now. By setting this to the same value as expected by the OS, we may save the latter a lot of live resampling.

fluidsynth/src/synth/fluid_synth.c

Line 231 in 0949617

fluid_settings_register_num(settings, "synth.sample-rate", 44100.0, 8000.0, 96000.0, 0);

[derselbst]

Unlikely to happen. FX parameters for chorus and reverb have been tuned to the default sample-rate of 44.1kHz. Also, I'm not aware of any spec that defines 48kHz to be "what the OS expects".