- fetch: check if errno == 14 before accessing the URLGrabError's code attribute

Unfortunately the class URLGrabError does not define constants for the
different error codes therefore we have to hardcode the errno (alternatively
we can define them in our fetch module).

osc/fetch.py

@@ -279,7 +279,7 @@ class Fetcher:
                 sys.exit(0)
             except URLGrabError as e:
                 # Not found is okay, let's go to the next project
-                if e.code != 404:
+                if e.errno == 14 and e.code != 404:
                     print("Invalid answer from server", e, file=sys.stderr)
                     sys.exit(1)