delete dead code [skip ci]
delete dead code [skip ci]

ButchersBoy/MaterialDesignInXamlToolkit,tipunch74/MaterialDesignInXamlToolkit,ButchersBoy/MaterialDesignInXamlToolkit,tipunch74/MaterialDesignInXamlToolkit,ButchersBoy/MaterialDesignInXamlToolkit,tipunch74/MaterialDesignInXamlToolkit,DingpingZhang/MaterialDesignInXamlToolkit