stack/erp5: Make bt5 default value a string at the last step.

Make the value and its changes easier to read.

stack/erp5/buildout.hash.cfg

@@ -78,7 +78,7 @@ md5sum = 68b329da9893e34099c7d8ad5cb9c940
 
 [template-erp5]
 filename = instance-erp5.cfg.in
-md5sum = 82dc695e212be124d60ceb1143e56b0d
+md5sum = 0920a53b10d3811a5f49930adffb62d8
 
 [template-zeo]
 filename = instance-zeo.cfg.in

stack/erp5/instance-erp5.cfg.in

@@ -176,11 +176,16 @@ return =
 {%- if test_runner_enabled %}
   test-runner-address-list
 {% endif %}
-{% set bt5_default_list = 'erp5_full_text_mroonga_catalog erp5_configurator_standard erp5_configurator_maxma_demo erp5_configurator_run_my_doc' -%}
+{% set bt5_default_list = [
+  'erp5_full_text_mroonga_catalog',
+  'erp5_configurator_standard',
+  'erp5_configurator_maxma_demo',
+  'erp5_configurator_run_my_doc',
+] -%}
 {% if has_jupyter -%}
-{%   set bt5_default_list = bt5_default_list + ' erp5_data_notebook' -%}
+{%   do bt5_default_list.append('erp5_data_notebook') -%}
 {% endif -%}
-config-bt5 = {{ dumps(slapparameter_dict.get('bt5', bt5_default_list)) }}
+config-bt5 = {{ dumps(slapparameter_dict.get('bt5', ' '.join(bt5_default_list))) }}
 config-bt5-repository-url = {{ dumps(slapparameter_dict.get('bt5-repository-url', local_bt5_repository)) }}
 config-cloudooo-url = {{ dumps(slapparameter_dict.get('cloudooo-url', default_cloudooo_url)) }}
 config-caucase-url = {{ dumps(caucase_url) }}