lang/janet: Update to v1.19.1

Changes:	https://github.com/janet-lang/janet/releases/tag/v1.19.1

lang/janet/Makefile

 PORTNAME=	janet
 DISTVERSIONPREFIX=	v
-DISTVERSION=	1.19.0
+DISTVERSION=	1.19.1
 CATEGORIES=	lang
 
 MAINTAINER=	tobik@FreeBSD.org

lang/janet/distinfo

-TIMESTAMP = 1638034177
-SHA256 (janet-lang-janet-v1.19.0_GH0.tar.gz) = 613f08613d524349bea9777d9f4f930252a0f035332da113c993153fe5284ef2
-SIZE (janet-lang-janet-v1.19.0_GH0.tar.gz) = 486549
+TIMESTAMP = 1638783428
+SHA256 (janet-lang-janet-v1.19.1_GH0.tar.gz) = b7f9ed8d192e70233dde4746cc5cd89c8f67e7605b08fa61d9af9d0cae471fe2
+SIZE (janet-lang-janet-v1.19.1_GH0.tar.gz) = 486506