#25 minor fix for running task on some platforms, tested on all units

Author: dave

src/TaskManagerIO.cpp

@@ -169,7 +169,7 @@ void TaskManager::cancelTask(taskid_t taskId) {
 void TaskManager::yieldForMicros(uint32_t microsToWait) {
 	yield();
 
-	auto& prevTask = runningTask;
+	auto* prevTask = getRunningTask();
 	unsigned long microsStart = micros();
 	do {
         runLoop();

src/TaskManagerIO.h

@@ -287,7 +287,7 @@ class TaskManager {
      * store this pointer.
      * @return a temporary pointer to the running task that lasts as long as it is running.
      */
-    const tm_internal::TimerTaskAtomicPtr& getRunningTask() { return runningTask; }
+    TimerTask* getRunningTask() { return runningTask; }
 
 private:
     /**