UE4 - when was 'remove selected' uv channel added?

aclund3

I'm trying to figure out what version of UE4 added the 'remove selected' UV channel feature.  We want to backport it into our editor, but I can't seem to find its implementation in the release notes.... I've been able to narrow it down from 4.16-4.21, but I'd super appreciate it if anyone knew specifically when that functionality came online.

Thanks!