programs: fix index table template

A column was missing in the header

app/templates/programs/index.html

@@ -17,7 +17,7 @@
 
   <h2>Tous les programmes</h2>
 	<table class=programlist>
-		<tr><th>ID</th><th>Nom</th><th>Auteur</th><th>Label</th><th>Progrank</th><th>Tags</th></tr>
+		<tr><th>ID</th><th>Nom</th><th>Auteur</th><th>Publication</th><th>Label</th><th>Progrank</th><th>Tags</th></tr>
 		{% for p in programs %}
 			<tr><td>{{ p.id }}</td>
 					<td><a href='{{ url_for("program_view", page=(p,1)) }}'>{{ p.name }}</a></td>