Disable REST API

Hi, the current rest routes used by our plugin are defined in https://github.com/perfectyorg/perfecty-push-wp/blob/master/public/class-perfecty-push-public.php#L90-L123

However they will change in 1.7.0, so please have the upcoming change in mind:

		// JS SDK friendly routes
		register_rest_route(
			'perfecty-push',
			'/v1/webpush/(?P<site_id>[a-zA-Z0-9-]+)/subscribers',
			array(
				'methods'             => array( 'POST' ),
				'callback'            => array( $users, 'register' ),
				'permission_callback' => '__return_true',
				'args'                => array( 'site_id' => array() ),
			)
		);
		register_rest_route(
			'perfecty-push',
			'/v1/webpush/(?P<site_id>[a-zA-Z0-9-]+)/subscribers/(?P<id>[a-zA-Z0-9-]+)/unregister',
			array(
				'methods'             => array( 'POST' ),
				'callback'            => array( $users, 'unregister' ),
				'permission_callback' => '__return_true',
				'args'                => array(
					'site_id'       => array(),
					'subscriber_id' => array(),
				),
			)
		);
		register_rest_route(
			'perfecty-push',
			'/v1/webpush/(?P<site_id>[a-zA-Z0-9-]+)/subscribers/(?P<id>[a-zA-Z0-9-]+)',
			array(
				'methods'             => array( 'GET' ),
				'callback'            => array( $users, 'get_user' ),
				'permission_callback' => '__return_true',
				'args'                => array(
					'site_id'       => array(),
					'subscriber_id' => array(),
				),
			)
		);