function plt_hide_multisite_toolbar_additions_menus() {
//Hide the "Appearance → Upload Theme ZIP" menu.
remove_submenu_page('themes.php', 'http://127.0.0.1/wp-admin/theme-install.php?tab=mstba-upload');
//Hide the "Plugins → Upload Plugin ZIP" menu.
remove_submenu_page('plugins.php', 'http://127.0.0.1/wp-admin/plugin-install.php?tab=upload');
}
add_action('admin_menu', 'plt_hide_multisite_toolbar_additions_menus', 1000);