Gui: modernize C++: use equals default

src/Gui/PreferencePages/DlgSettingsNavigation.cpp

@@ -64,9 +64,7 @@ DlgSettingsNavigation::DlgSettingsNavigation(QWidget* parent)
 /**
  *  Destroys the object and frees any allocated resources
  */
-DlgSettingsNavigation::~DlgSettingsNavigation()
-{
-}
+DlgSettingsNavigation::~DlgSettingsNavigation() = default;
 
 void DlgSettingsNavigation::saveSettings()
 {
@@ -342,9 +340,7 @@ CameraDialog::CameraDialog(QWidget* parent)
             &CameraDialog::onCurrentViewClicked);
 }
 
-CameraDialog::~CameraDialog()
-{
-}
+CameraDialog::~CameraDialog() = default;
 
 void CameraDialog::setValues(double q0, double q1, double q2, double q3)
 {