Update services.md

[jrioscloud]

I've removed duplicated code

[jtoar]

thanks @papaponmx!

[pvenable]

FWIW I don't think this was duplicate code per se. It was showing two different ways of throwing errors, and without both examples the next sentence doesn't make much sense anymore:

Either of these errors will be caught and re-thrown as a ServiceValidationError with your text as the message of the error (although technically you should always throw errors with new Error() like in the second example).

[jtoar]

thanks for catching that @pvenable totally missed it. maybe we need to add a comment in the codeblock that highlights the difference a bit. but will revert!