Interruption needs to be handled through the exception handling mecha…

…nism (#480)

src/main/java/com/pivovarit/collectors/Dispatcher.java

@@ -52,7 +52,7 @@ void start() {
         started = true;
         dispatcher.execute(() -> {
             try {
-                while (!Thread.currentThread().isInterrupted()) {
+                while (true) {
                     Runnable task;
                     if ((task = workingQueue.take()) != POISON_PILL) {
                         limiter.acquire();