avoid blocking shutdown to see if that's what hangs

Author: Simn

src/hxcoro/CoroRun.hx

@@ -141,7 +141,7 @@ class CoroRun {
 			}
 		}
 
-		pool.shutdown(true);
+		pool.shutdown(false);
 
 		switch (scope.getError()) {
 			case null:

src/hxcoro/thread/FixedThreadPool.hx

@@ -60,8 +60,6 @@ class FixedThreadPool implements IThreadPool {
 	final queue:DispatchQueue;
 	final thread:Thread;
 
-	final shutdownCounter = new AtomicInt(0);
-
 	/**
 		Create a new thread pool with `threadsCount` threads.
 	**/
@@ -108,9 +106,6 @@ class FixedThreadPool implements IThreadPool {
 	public function shutdown(block:Bool = false):Void {
 		if(_isShutdown) return;
 		_isShutdown = true;
-		if (block) {
-			shutdownCounter.store(pool.length);
-		}
 
 		function unlock() {