Fix simple print layout to not include an additional blank page

This magic number adjustment is due to a very ugly bug in Chromium.

aleksis/core/templates/core/base_simple_print.html

@@ -40,7 +40,7 @@
 
       .sheet {
         width: {{ width }}mm;
-        height: {{ height|add:-1 }}.83mm;
+        height: {{ height|add:-1 }}.73mm;
       } 
     </style>
   {% endblock %}