Let Python network Transport retry if endpoint is missing

If the endpoint (such as Luxid or WConfd) isn't running, don't fail
immediately. Instead retry (within the given timeout) and try to
reconnect.
Signed-off-by: Petr Pudlak <pudlak@google.com>
Reviewed-by: Klaus Aehlig <aehlig@google.com>

lib/rpc/transport.py

@@ -107,7 +107,7 @@ class Transport:
     except socket.error, err:
       error_code = err.args[0]
       if error_code in (errno.ENOENT, errno.ECONNREFUSED):
-        raise errors.NoMasterError(address)
+        raise utils.RetryAgain()
       elif error_code in (errno.EPERM, errno.EACCES):
         raise errors.PermissionError(address)
       elif error_code == errno.EAGAIN: