fff-web-ui: Only show batman-adv data if batctl exists

To prevent the follow error in logread at layer 3 firmware:

uhttpd[1700]: /bin/sh: batctl: not found

remove batctl from webui if no batctl exist

Signed-off-by: Christian Dresel <freifunk@dresel.systems>

src/packages/fff/fff-web-ui/files/www/public/cgi-bin/status.html

@@ -57,6 +57,7 @@ contact="$(uci -q get "fff.system.contact")"
 							</table>
 						</fieldset>
 					</td><td>
+						<% if [ -f "$(command -v batctl)" ] ; then %>
 						<fieldset style="min-height: 15em;">
 							<legend>Status</legend>
 							<table>
@@ -66,6 +67,7 @@ contact="$(uci -q get "fff.system.contact")"
 								<tr><th>Lokale Clients:</th><td><% echo -n $(batctl tl -H 2> /dev/null | grep -c 'W') %></td></tr>
 							</table>
 						</fieldset>
+						<% fi %>
 					</td></tr>
 				</table>
 			</div>