There's a closed pull request on the void-packages repository

New package: rsgain-3.4.0
https://github.com/void-linux/void-packages/pull/48591

Description:
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rsgain (really simple gain) is a very heavily modified fork of [loudgain](https://github.com/Moonbase59/loudgain), and is licensed accordingly under the original 2 clause BSD license used by loudgain. 

#### Testing the changes
- I tested the changes in this PR: **YES**

#### New package
- This new package conforms to the [package requirements](https://github.com/void-linux/void-packages/blob/master/CONTRIBUTING.md#package-requirements): **YES**

#### Local build testing
- I built this PR locally for my native architecture, x86_64-glibc
- I built this PR locally for these architectures (if supported. mark crossbuilds):
  - armv7l (only compiled, not tested)