Replace asyncio.async with ensure_future because of deprecation, Fixes: #1269

gns3server/controller/gns3vm/__init__.py

@@ -302,7 +302,7 @@ class GNS3VM:
 
             # check if the VM is in the same subnet as the local server, start 10 seconds later to give
             # some time for the compute in the VM to be ready for requests
-            asyncio.get_event_loop().call_later(10, lambda: asyncio.async(self._check_network(compute)))
+            asyncio.get_event_loop().call_later(10, lambda: asyncio.ensure_future(self._check_network(compute)))
 
     @asyncio.coroutine
     def _check_network(self, compute):