productivity/taskwarrior: fix homepage url

Here is a very small patch to fix taskwarrior's URL in the Makefile.

Thanks!

Index: Makefile
===================================================================
RCS file: /cvs/ports/productivity/taskwarrior/Makefile,v
retrieving revision 1.30
diff -u -p -u -p -r1.30 Makefile
--- Makefile 3 Jun 2018 11:20:18 -0000 1.30
+++ Makefile 23 May 2019 22:33:05 -0000
@@ -6,9 +6,9 @@ VERSION = 2.5.1
DISTNAME = task-${VERSION}
PKGNAME = taskwarrior-${VERSION}
CATEGORIES = productivity
-REVISION = 2
+REVISION = 3

-HOMEPAGE = https://tawww.skwarrior.org/
+HOMEPAGE = https://www.taskwarrior.org/

MAINTAINER = Jasper Lievisse Adriaanse <jasper@openbsd.org>