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

mbuffer: update to 20210209
https://github.com/void-linux/void-packages/pull/29352

Description:
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#### Have the results of the proposed changes been tested?
- [x] I use the packages affected by the proposed changes on a regular basis and confirm this PR works for me
- [ ] I generally don't use the affected packages but briefly tested this PR

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