Fix pkg.conf generation by the installer.

ever since we moved our mirror path format (over a year ago) this regex
has been plain wrong and just meaning that no new install gets a
pkg.conf. We can actualy simplify here since in our format thep ackages
dir is always a subdir of the release dir. So jus append /packages and
call it a good 'un.

tested by jcv@ for whom this previously failed.

ok drahn, jcv.

distrib/miniroot/install.sub

@@ -1423,9 +1423,7 @@ install_http() {
 	# Bake a package path only if we installed from a mirror.
 	PACKAGE_PATH=
 	if [[ -n $_mirror ]]; then
-		PACKAGE_PATH=$(print -r -- "$_url_base" |
-			sed -E "/\/(snapshots|[0-9]\.[0-9])\/($ARCH)\/*$/!d
-				s!!/\1/packages/$(arch -s)/!;q")
+		PACKAGE_PATH=$(print -r -- "$_url_base")/packages
 	fi
 }