New review comment by Piraty on void-packages repository

https://github.com/void-linux/void-packages/pull/33319#discussion_r723672275

Comment:
`-O2` is the default
https://github.com/void-linux/void-packages/blob/541bb0ea7d5480c51b245cae5d44a93da1fd9211/etc/defaults.conf#L31-L32