Remove unused methods, and make the field final

Author: Vlatombe

core/src/main/java/hudson/model/Queue.java

@@ -2672,15 +2672,7 @@ protected NotWaitingItem(NotWaitingItem ni) {
      * {@link Item} in the {@link Queue#blockedProjects} stage.
      */
     public final class BlockedItem extends NotWaitingItem {
-        private transient CauseOfBlockage causeOfBlockage = null;
-
-        public BlockedItem(WaitingItem wi) {
-            this(wi, null);
-        }
-
-        public BlockedItem(NotWaitingItem ni) {
-            this(ni, null);
-        }
+        private final transient CauseOfBlockage causeOfBlockage;
 
         BlockedItem(WaitingItem wi, CauseOfBlockage causeOfBlockage) {
             super(wi);
@@ -2692,10 +2684,6 @@ public BlockedItem(NotWaitingItem ni) {
             this.causeOfBlockage = causeOfBlockage;
         }
 
-        void setCauseOfBlockage(CauseOfBlockage causeOfBlockage) {
-            this.causeOfBlockage = causeOfBlockage;
-        }
-
         @Restricted(NoExternalUse.class)
         public boolean isCauseOfBlockageNull() {
             if (causeOfBlockage == null) {