Notify all workers when adjusting thread count

If we decreased the number of workers, then it may be possible
that the remaining workers are parked and need to drain tasks.

Author: Spottedleaf

src/main/java/ca/spottedleaf/concurrentutil/executor/thread/BalancedPrioritisedThreadPool.java

@@ -199,6 +199,10 @@ public void adjustThreadCount(final int threads) {
                 }
             }
         }
+
+        for (final WorkerThread thread : this.threads.getArray()) {
+            thread.notifyTasks();
+        }
     }
 
     public OrderedStreamGroup createOrderedStreamGroup() {