auto-t: fix get_ordered_network if hostapd isn't running

This API optimizes scanning to run tests quickly by only scanning
the frequencies which hostapd is using. But if a test doesn't use
hostapd this API raises an uncaught exception.

Check if hostapd is being used, and if not just do a full scan.

autotests/util/iwd.py

@@ -519,7 +519,8 @@ class Device(IWDDBusAbstract):
         IWD._wait_for_object_condition(self, condition)
 
         try:
-            if full_scan:
+            # Do a full scan if instructed or if hostapd isn't being used
+            if full_scan or not ctx.hostapd:
                 self.scan()
             else:
                 self.debug_scan(ctx.get_frequencies())