Exception when client not in leases

Client can be dropped from leases list from where the status is
retreived before it is dropped from the ip neigh list.
The client needs a default status.

homeassistant/components/device_tracker/asuswrt.py

@@ -157,7 +157,8 @@ class AsusWrtDeviceScanner(object):
             devices[match.group('ip')] = {
                 'ip': match.group('ip'),
                 'mac': match.group('mac').upper(),
-                'host': match.group('host')
+                'host': match.group('host'),
+                'status': ''
                 }
 
         for neighbor in neighbors: