Do in parallel block throws an error if there's no input.

when I was testing the do in parallel block, I clicked on it with no inputs, well, no blocks in the loops, and it thew an error, expecting ring but getting nothing. I think it should not do that. I've fixed it to check whether the item is nothing or a ring

Thank you. I made a PR fixing this and the "and wait" version. Instead of testing for an empty string I tested for item 1 of actions being a command.