devel/py-about-time: Convert to USE_PYTHON=pep517

- Bump PORTREVISION for package change

devel/py-about-time/Makefile

 PORTNAME=	about-time
 PORTVERSION=	4.2.1
+PORTREVISION=	1
 CATEGORIES=	devel python
 MASTER_SITES=	PYPI
 PKGNAMEPREFIX=	${PYTHON_PKGNAMEPREFIX}
@@ -11,8 +12,11 @@ WWW=		https://github.com/rsalmei/about-time
 LICENSE=	MIT
 LICENSE_FILE=	${WRKSRC}/LICENSE
 
+BUILD_DEPENDS=	${PYTHON_PKGNAMEPREFIX}setuptools>=0:devel/py-setuptools@${PY_FLAVOR} \
+		${PYTHON_PKGNAMEPREFIX}wheel>=0:devel/py-wheel@${PY_FLAVOR}
+
 USES=		python
-USE_PYTHON=	autoplist concurrent distutils
+USE_PYTHON=	autoplist concurrent pep517
 
 NO_ARCH=	yes