Remove increased leader-actions-interval, since it's false safety, see #2444

akka-cluster/src/multi-jvm/scala/akka/cluster/JoinInProgressSpec.scala

@@ -25,7 +25,7 @@ object JoinInProgressMultiJvmSpec extends MultiNodeConfig {
               threshold = 4
               acceptable-heartbeat-pause = 1 second
             }
-          }""") // increase the leader action task interval
+          }""")
         .withFallback(MultiNodeClusterSpec.clusterConfig)))
 }