Bug#970631: Pitch bend of Calf Fluidsynth plugin does not work except on channel 1

[Takeshi Soejima]

The patch has been merged to upstream. So this bug can be closed if the
package is updated by the upstream after 2020-11-7.

  
https://github.com/calf-studio-gear/calf/commit/083b7497a8429fe9f1e12e1b53fae439c21414e4