Filter support for Docker

Fix #1110

gns3server/compute/base_manager.py

@@ -373,7 +373,7 @@ class BaseManager:
                         sock.connect(sa)
             except OSError as e:
                 raise aiohttp.web.HTTPInternalServerError(text="Could not create an UDP connection to {}:{}: {}".format(rhost, rport, e))
-            filters = nio_settings.get("filters", [])
+            filters = nio_settings.get("filters", {})
             nio = NIOUDP(lport, rhost, rport, filters)
         elif nio_settings["type"] == "nio_tap":
             tap_device = nio_settings["tap_device"]