=clu #13875 Fix regression in leader selection

* The leader is selected by picking the first reachable member, but in
  #13875 we had to let the self member be unreachable in the Reachability
  table and that was not considered in the logic of the leader selection.
* That means changed behavior that is unwanted, especially when there
  is only one node left the leader could be evaluated to None instead
  of Some(selfUniqueAddress).
* Note that #13875 has not been released yet.

akka-cluster/src/main/scala/akka/cluster/ClusterDaemon.scala

@@ -760,7 +760,7 @@ private[cluster] class ClusterCoreDaemon(publisher: ActorRef) extends Actor with
    * Runs periodic leader actions, such as member status transitions, assigning partitions etc.
    */
   def leaderActions(): Unit =
-    if (latestGossip.isLeader(selfUniqueAddress)) {
+    if (latestGossip.isLeader(selfUniqueAddress, selfUniqueAddress)) {
       // only run the leader actions if we are the LEADER
       val firstNotice = 20
       val periodicNotice = 60