Sequence headers are always shown.

I wasn't sure if that was the case, but I've checked nevow now.

src/allmydata/web/common.py

@@ -466,13 +466,6 @@ class SlotsSequenceElement(template.Element):
         self.loader = template.TagLoader(tag)
         self.seq = seq
 
-    @template.renderer
-    def header(self, request, tag):
-        if len(self.seq) > 0:
-            return tag
-        else:
-            return ''
-
     @template.renderer
     def item(self, request, tag):
         for item in self.seq:

src/allmydata/web/introducer.xhtml

@@ -26,7 +26,7 @@
 <div class="section">
 <h2>Service Announcements</h2>
 <table class="services table-headings-top" t:render="services">
-  <tr t:render="header">
+  <tr>
     <th class="nickname-and-peerid">
       <div class="service-nickname">Nickname</div>
       <div class="nodeid data-chars">ServerID</div></th>
@@ -50,7 +50,7 @@
 <div>
 <h2>Subscribed Clients</h2>
 <table class="services table-headings-top" t:render="subscribers">
-  <tr t:render="header">
+  <tr>
     <th class="nickname-and-peerid">
       <div class="service-nickname">Nickname</div>
       <div class="nodeid data-chars">Tub ID</div></th>