Mesh: modernize C++: use equals default

src/Mod/Mesh/Gui/DlgRegularSolidImp.cpp

@@ -100,10 +100,7 @@ DlgRegularSolidImp::DlgRegularSolidImp(QWidget* parent, Qt::WindowFlags fl)
 /**
  *  Destroys the object and frees any allocated resources
  */
-DlgRegularSolidImp::~DlgRegularSolidImp()
-{
-    // no need to delete child widgets, Qt does it all for us
-}
+DlgRegularSolidImp::~DlgRegularSolidImp() = default;
 
 void DlgRegularSolidImp::changeEvent(QEvent *e)
 {