Fix missing csrf token in series grid view

cps/templates/grid.html

@@ -8,6 +8,7 @@
         <button id="sort_name" class="btn btn-primary"><b>B,A <-> A B</b></button>
        {% endif %}
       {% endif %}
+      <input type="hidden" name="csrf_token" value="{{ csrf_token() }}">
       <button id="asc" data-id="series" data-order="{{ order }}" class="btn btn-primary"><span class="glyphicon glyphicon-sort-by-alphabet"></span></button>
       <button id="desc" data-id="series" class="btn btn-primary"><span class="glyphicon glyphicon-sort-by-alphabet-alt"></span></button>
       {% if charlist|length %}