mastodon/mastodon#16221 is merged and comment is outdated

[This comment](https://github.com/mastodon/chart/blob/4b6fd9f7e6273cb2708e5f8e16b87b1d07114eb8/values.yaml#L292) says, that mastodon/mastodon#16221 will be merged soon, but has been already. Just to avoid some confusion, i think this should be rephrased.