Catch possible errors from tradfri (#17068)

* Catch possible errors from tradfri

* Update config_flow.py

homeassistant/components/tradfri/config_flow.py

@@ -169,7 +169,9 @@ async def get_gateway_info(hass, host, identity, key):
         api = factory.request
         gateway = Gateway()
         gateway_info_result = await api(gateway.get_gateway_info())
-    except RequestError:
+    except (OSError, RequestError):
+        # We're also catching OSError as PyTradfri doesn't catch that one yet
+        # Upstream PR: https://github.com/ggravlingen/pytradfri/pull/189
         raise AuthError('cannot_connect')
 
     return {