Fix file uploads (borken by missing enctype on form)

nummi/main/templates/main/form/base.html

@@ -34,7 +34,7 @@
             </h2>
         {% endif %}
         {% block pre %}{% endblock %}
-        <form method="post">
+        <form method="post" enctype="multipart/form-data">
             {% csrf_token %}
             {% if instance|adding %}<input hidden name="next" value="{{ request.path }}" />{% endif %}
             {{ form }}