caddy-frontend: Allow to override parameters

As there is some kind of "collision" with request, allow to override
parameters.

Treat `<key>` as default and overwrite it with `frontend-config-<num>-<key>`,
instead of having the global `<key>` always passed to slaves.

This allows to request the partition with:

  monitor-httpd-frontend=12345
  -frontend-config-1-monitor-httpd-frontend=9876
  -frontend-config-1-monitor-httpd-frontend=8765

software/caddy-frontend/buildout.hash.cfg

@@ -22,7 +22,7 @@ md5sum = 2db996d2c48c0fe03c05f051e7a914bc
 
 [template-apache-replicate]
 filename = instance-apache-replicate.cfg.in
-md5sum = a30d4bc21ae94d0eca42cea5032468a8
+md5sum = a757e014f362c3db3c2717cc5b4102ab
 
 [template-slave-list]
 filename = templates/apache-custom-slave-list.cfg.in

software/caddy-frontend/instance-apache-replicate.cfg.in

@@ -100,8 +100,8 @@ name = {{ frontend_request.get('name') }}
 {%   if frontend_request.get('state') %}
 state = {{ frontend_request.get('state') }}
 {%   endif%}
-{%   set slave_configuration_dict = frontend_request.get('config') %}
-{%   do slave_configuration_dict.update(**slapparameter_dict) %}
+{%   set slave_configuration_dict = slapparameter_dict %}
+{%   do slave_configuration_dict.update(frontend_request.get('config')) %}
 {%   do slave_configuration_dict.__setitem__(slave_list_name, json_module.dumps(authorized_slave_list)) %}
 {%   do slave_configuration_dict.__setitem__("frontend-name", frontend_request.get('name')) %}
 config-_ = {{ json_module.dumps(slave_configuration_dict) }}