[css-ui-4] Fix bikeshed status

Author: frivoal

css-ui-4/Overview.bs

@@ -23,6 +23,7 @@ Previous Version: https://www.w3.org/TR/2017/WD-css-ui-4-20171222/
 Previous Version: https://www.w3.org/TR/2015/WD-css-ui-4-20150922/
 Shortname: css-ui
 Level: 4
+Status: ED
 Group: csswg
 Work Status: Revising
 Editor: Florian Rivoal, On behalf of Bloomberg, https://florian.rivoal.net/, w3cid 43241