copr: stg-backend: fix lighttpd config for certbot

- server.document-root is not needed /.well-known/
- alias.url needs mod_alias loaded

roles/copr/backend/files/lighttpd/lighttpd_dev.conf

@@ -77,6 +77,7 @@ var.socket_dir  = home_dir + "/sockets"
 ## Load the modules.
 #include "modules.conf"
 server.modules = (
+  "mod_alias", # for /.well-known/ alias
   "mod_access",
   "mod_setenv",
   "mod_redirect",
@@ -452,7 +453,6 @@ server.upload-dirs = ( "/var/tmp" )
 
 # Used for letsencrypt validation
 $HTTP["url"] =~ "^/.well-known/" {
-    server.document-root = "/var/certbot/public_html/.well-known/"
     alias.url = ( "/.well-known/" => "/var/certbot/public_html/.well-known/" )
     dir-listing.activate = "enable"
 }