Use asyncio.ensure_future() instead of asyncio.async() with conservative approach to support Python < 3.4.4. Fixes https://github.com/GNS3/gns3-gui/issues/2566

gns3server/compute/vmware/__init__.py

@@ -32,6 +32,7 @@ import shlex
 from collections import OrderedDict
 from gns3server.utils.interfaces import interfaces
 from gns3server.utils.asyncio import subprocess_check_output
+from gns3server.utils.asyncio import asyncio_ensure_future
 from gns3server.utils import parse_version
 
 log = logging.getLogger(__name__)
@@ -738,4 +739,4 @@ if __name__ == '__main__':
     loop = asyncio.get_event_loop()
     vmware = VMware.instance()
     print("=> Check version")
-    loop.run_until_complete(asyncio.async(vmware.check_vmware_version()))
+    loop.run_until_complete(asyncio_ensure_future(vmware.check_vmware_version()))