Add missing /etc/mailman symlink

build.sh

@@ -83,7 +83,7 @@ done
 # as above but with the /config mountpoint.
 mkdir -p /config
 rm -f /etc/mailman/mm_cfg.py
-for f in mm_cfg.py mailman_api.conf forced_params ; do
+for f in mm_cfg.py mailman_api.conf domains forced_params ; do
     ln -s /config/$f /etc/mailman/$f
 done