Fix CSRF Login issues, adjust PAPERLESS_URL environment variable reference

`PAPERLESS_URL` has to be without port reference to avoid Django CSRF issues when logging in. Otherwise the trusted origin in Django will be set to the url with port

templates/compose/paperless.yaml

@@ -37,7 +37,7 @@ services:
         is_directory: true
     environment:
       - SERVICE_URL_PAPERLESS_8000
-      - PAPERLESS_URL=$SERVICE_URL_PAPERLESS_8000
+      - PAPERLESS_URL=$SERVICE_URL_PAPERLESS
       - PAPERLESS_ADMIN_PASSWORD=${SERVICE_PASSWORD_PAPERLESS}
       - PAPERLESS_ADMIN_USER=${SERVICE_USER_PAPERLESS}
       - PAPERLESS_REDIS=redis://redis:6379