fix crash in shutdown

libguh-core/guhcore.cpp

@@ -121,13 +121,17 @@ GuhCore *GuhCore::instance()
 GuhCore::~GuhCore()
 {
     m_logger->logSystemEvent(m_timeManager->currentDateTime(), false);
+
+    // Make sure DeviceManager is teared down at first so plugins don't access any ressources any more.
+    delete m_deviceManager;
 }
 
 /*! Destroyes the \l{GuhCore} instance. */
 void GuhCore::destroy()
 {
-    if (s_instance)
+    if (s_instance) {
         delete s_instance;
+    }
 
     s_instance = 0;
 }

libguh-core/hardwaremanagerimplementation.cpp

@@ -84,6 +84,11 @@ HardwareManagerImplementation::HardwareManagerImplementation(QObject *parent) :
     qCDebug(dcHardware()) << "HardwareManager D-Bus service set up.";
 }
 
+HardwareManagerImplementation::~HardwareManagerImplementation()
+{
+    qCDebug(dcApplication()) << "Shutting down Hardware Manager";
+}
+
 Radio433 *HardwareManagerImplementation::radio433()
 {
     return m_radio433;

libguh-core/hardwaremanagerimplementation.h

@@ -49,6 +49,7 @@ class HardwareManagerImplementation : public HardwareManager
 
 public:
     explicit HardwareManagerImplementation(QObject *parent = nullptr);
+    ~HardwareManagerImplementation();
 
     Radio433 *radio433();
     PluginTimerManager *pluginTimerManager();