Mod: modernize C++: use equals default

src/Mod/Test/Gui/AppTestGui.cpp

@@ -137,8 +137,6 @@ public:
         initialize("This module is the QtUnitGui module"); // register with Python
     }
 
-    ~Module() override {}
-
 private:
     Py::Object new_UnitTest(const Py::Tuple& args)
     {

src/Mod/Test/Gui/UnitTestImp.cpp

@@ -96,9 +96,7 @@ UnitTestDialog::UnitTestDialog(QWidget* parent, Qt::WindowFlags f)
 /**
  *  Destroys the object and frees any allocated resources
  */
-UnitTestDialog::~UnitTestDialog()
-{
-}
+UnitTestDialog::~UnitTestDialog() = default;
 
 void UnitTestDialog::setupConnections()
 {

src/Mod/Test/Gui/UnitTestPy.cpp

@@ -60,13 +60,9 @@ void UnitTestDialogPy::init_type()
     add_varargs_method("clearUnitTests",&UnitTestDialogPy::clearUnitTests,"clearUnitTests");
 }
 
-UnitTestDialogPy::UnitTestDialogPy()
-{
-}
+UnitTestDialogPy::UnitTestDialogPy() = default;
 
-UnitTestDialogPy::~UnitTestDialogPy()
-{
-}
+UnitTestDialogPy::~UnitTestDialogPy() = default;
 
 Py::Object UnitTestDialogPy::repr()
 {