Fix scaladoc-js HTML.Tag unchecked patmat

Author: dwijnand

scaladoc-js/common/src/utils/html.scala

@@ -26,7 +26,7 @@ object HTML {
         case ("id", id) => elem.id = id
         case ("class", value) => value.split("\\s+").foreach(cls => elem.classList.add(cls))
         case (attr, value) => elem.setAttribute(attr, value)
-        case s: Seq[AppliedAttr] => unpackAttributes(s*)
+        case s: Seq[AppliedAttr @unchecked] => unpackAttributes(s*)
       }
 
       unpackTags(tags*)
@@ -118,4 +118,4 @@ object HTML {
   val titleAttr =Attr("title")
   val onkeyup = Attr("onkeyup")
 
-}
+}