contrib/package/freifunk-p2pblock: do not start if no wan interface is present (spotted on the fonera)

contrib/package/freifunk-p2pblock/files/freifunk-p2pblock.init

@@ -19,6 +19,8 @@ start() {
 		
 		config_load network
 		config_get wan wan ifname
+
+		if [ -n "$wan" ]; then
 			config_load freifunk_p2pblock
 			config_get layer7 p2pblock layer7
 			config_get ipp2p p2pblock ipp2p
@@ -58,10 +60,11 @@ start() {
 			done
 
 			logger -s -t "$ME" 'Done.'; return 0
-
+		else
+			logger -s -t "$ME" 'No wan interface present.'; return 0	
+		fi
 	else
 		logger -s -t "$ME" 'WARNING! already running - Aborting!'; return 2
-
 	fi
 }