graphics/avir: Update 2.7 -> 2.8

Reported by:	portscout

graphics/avir/Makefile

 PORTNAME=	avir
-DISTVERSION=	2.7
+DISTVERSION=	2.8
 CATEGORIES=	graphics
 
 MAINTAINER=	yuri@FreeBSD.org

graphics/avir/distinfo

-TIMESTAMP = 1618273881
-SHA256 (avaneev-avir-2.7_GH0.tar.gz) = 7b77af9f43835b0eacc2841daf72a7177b0148b588e12645be835aab2754e154
-SIZE (avaneev-avir-2.7_GH0.tar.gz) = 1893869
+TIMESTAMP = 1618560851
+SHA256 (avaneev-avir-2.8_GH0.tar.gz) = c9f95eef1abe4db534b311f39ca47adefc12f0517aca9f1370c5fbc36f70da83
+SIZE (avaneev-avir-2.8_GH0.tar.gz) = 1917675