devel/py-libzfs: Update GH_ACCOUNT, fix build on legacy ZFS

Make lzc_wait conditional on support in ZFS, since it is a relatively
recent addition.

While here, update GH_ACCOUNT to truenas as suggested by diizzy.

Reviewed by:	kbowling
Approved by:	kbowling (ports)
Sponsored by:	iXsystems, Inc.
Differential Revision:	https://reviews.freebsd.org/D31394

devel/py-libzfs/Makefile

 # Created by: William Grzybowski <wg@FreeBSD.org>
 
 PORTNAME=	libzfs
-PORTVERSION=	1.1.2021073000
+PORTVERSION=	1.1.2021080300
 CATEGORIES=	devel python
 PKGNAMEPREFIX=	${PYTHON_PKGNAMEPREFIX}
 
@@ -11,9 +11,9 @@ COMMENT=	Python libzfs bindings
 LICENSE=	BSD2CLAUSE
 
 USE_GITHUB=     yes
-GH_ACCOUNT=	freenas
+GH_ACCOUNT=	truenas
 GH_PROJECT=	py-libzfs
-GH_TAGNAME=	83b52494
+GH_TAGNAME=	7a5e3e3
 
 HAS_CONFIGURE=	yes
 USES=		compiler:c11 python:3.6+

devel/py-libzfs/distinfo

-TIMESTAMP = 1627688919
-SHA256 (freenas-py-libzfs-1.1.2021073000-83b52494_GH0.tar.gz) = 0b0e138034ca6a4922fb39012158c2ef37252fc5b23d8b00d62f1987fff7acb2
-SIZE (freenas-py-libzfs-1.1.2021073000-83b52494_GH0.tar.gz) = 91247
+TIMESTAMP = 1627964216
+SHA256 (truenas-py-libzfs-1.1.2021080300-7a5e3e3_GH0.tar.gz) = b0a4f21575cfb08518c54b3ea922ed39397da191ef7718f1145f0317c4880b15
+SIZE (truenas-py-libzfs-1.1.2021080300-7a5e3e3_GH0.tar.gz) = 91390