Role ipt-server: migrate o13-git, first install on h.mx, remove obsolete host_vars of oolm-db.

o13-git was removed from no_ipt_firewall (hosts, already in 57970a6).
h.mx gets the same dovecot auth networks as a.mx.
oolm-db.oopen.de is identical to o21.oopen.de.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

host_vars/o13-git.oopen.de/o13-git-ipt-server.yml

@@ -3,7 +3,7 @@
 # Generated by extract-fw-host-vars.py - review before committing!
 # Place in: host_vars/<hostname>/<short-hostname>-ipt-server.yml
 
-fw_manage_config: false
+fw_manage_config: true
 
 # --- Network
 fw_ext_interfaces: