Fix color of latest-posts in editor if block is grouped with background-color (#681)

Author: albig

assets/css/editor-style.css

@@ -521,3 +521,6 @@ p a {
 	padding-left: 5vw;
 	padding-right: 5vw;
 }
+.bg-white {
+    background-color: #fff;
+}