nixos/tests/sslh: Use curl --fail

Changed files
+1 -1
nixos
tests
+1 -1
nixos/tests/sslh.nix
···
server.succeed(f"grep '{ip}' /tmp/foo{arg}")
# check that http through sslh works
-
assert client.succeed(f"curl {arg} http://server:443").strip() == "hello world"
+
assert client.succeed(f"curl -f {arg} http://server:443").strip() == "hello world"
'';
}