copr: be-dev: drop mod_alias config for letsencrypt

The alias hack is not needed because the certbot binary is run as root,
and so we can (and we do) use /var/lib/copr/public_html as challenge
directory (configured in inventory/group_vars/copr_back_dev).

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

@@ -77,7 +77,6 @@ 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",
@@ -454,7 +453,6 @@ server.upload-dirs = ( "/var/tmp" )
 
 # Used for letsencrypt validation
 $HTTP["url"] =~ "^/.well-known/" {
-    alias.url = ( "/.well-known/" => "/var/certbot/public_html/.well-known/" )
     dir-listing.activate = "enable"
 }