Update code

forge-game/src/main/java/forge/game/card/Card.java

@@ -5463,17 +5463,12 @@ public class Card extends GameEntity implements Comparable<Card> {
     public String getKeywordKey() {
         String sorted = "";
         List<String> ability = new ArrayList<>();
-        ability.clear();
         for (final KeywordInterface inst : getKeywords()) {
             String kw = inst.getOriginal();
             ability.add(kw);
         }
-        if (ability != null) {
         Collections.sort(ability);
-            for (final String s : ability){
-                sorted += s + ",";
-            }
-        }
+        sorted = String.join(",", ability);
         return sorted;
     }
     public Zone getZone() {