archweb: avoid a redirect when redirecting

planet.archlinux.org redirects to https://archlinux.org/planet which
then redirects to https://archlinux.org/planet/. Skip one extra
redirect.

roles/archweb/defaults/main.yml

@@ -3,7 +3,7 @@ archweb_domain: 'archlinux.org'
 archweb_alternate_domains: ['www.archlinux.org', 'master-key.archlinux.org', 'dev.archlinux.org', 'packages.archlinux.org', 'ipxe.archlinux.org', 'planet.archlinux.org']
 archweb_domains_redirects:
         'www.archlinux.org': '$request_uri'
-        'master-key.archlinux.org': '/master-keys'
+        'master-key.archlinux.org': '/master-keys/'
         'dev.archlinux.org': '/'
         'packages.archlinux.org': '/packages$request_uri'
         'planet.archlinux.org': '/planet$request_uri'