welcome_new can be NULL, so use "" instead of rendering "None".

 - Legacy-Id: 514

Author: fenner

ietf/templates/mailinglists/list_summary.html

@@ -10,7 +10,7 @@
 <tr><td> Administrator(s): </td><td><pre>{{ list.admins|escape }}</pre></td></tr>
 <tr><td> Email address(es) of initial subscriber(s) (optional): </td><td><pre>{{ list.initial_members|escape }}</pre></td></tr>
 <tr><td> Welcome message for initial subscriber(s) (optional): </td><td>{{ list.welcome_message|linebreaksbr }}</td></tr>
-<tr><td> Welcome message for new subscriber(s) (optional): </td><td>{{ list.welcome_new|linebreaksbr }}</td></tr>
+<tr><td> Welcome message for new subscriber(s) (optional): </td><td>{% filter linebreaksbr %}{% firstof list.welcome_new "" %}{% endfilter %}</td></tr>
 <tr><td> Required steps for subscription: </td><td>{{ list.get_subscription_display }}</td></tr>
 <tr><td> Messages to this list can be posted by:</td><td>{{ list.get_post_who_display }}</td></tr>
 <tr><td> Administrator approval required for posts: </td><td>{{ list.post_admin|yesno:"YES,NO" }}</td></tr>

ietf/templates/mailinglists/list_summary.txt

@@ -23,7 +23,7 @@ Welcome message for initial subscriber(s) (optional):
 {{ list.welcome_message }}
 
 Welcome message for new subscriber(s) (optional):
-{{ list.welcome_new }}
+{% firstof list.welcome_new "" %}
 
 Required steps for subscription: {{ list.get_subscription_display }}