Allow wildcard DnsEntry

Simple fix

We use the API to provision domains at `*.stage.inventid.us`, however your implementation did not allow that. It turned out it did not adequately urlencode the `*` symbol. In return TransIP therefore denied the request.

This simple one-liner fixes it, although it cost me quite a bit of time.

In order to allow for easy merging I have not cleaned up any old code and gone for the easy solution.