Fix includes in parented_ptr.h

Author: daschuer

src/util/parented_ptr.h

@@ -1,13 +1,10 @@
 #pragma once
 
-#ifdef MIXXX_DEBUG_ASSERTIONS_ENABLED
 #include <QObject>
-#endif
 #include <QPointer>
 #include <memory>
 
 #include "util/assert.h"
-#include "util/parented_ptr.h"
 
 // Use this wrapper class to clearly represent a raw pointer that is owned by the QT object tree.
 // Objects which both derive from QObject AND have a parent object, have their lifetime governed by