Sp6.sc1.error message bug

Now the error messages wont crash. Before, all errors would crash since they tried to do lib_json:encode on an atom.

erlastic_search will return {error, atom} in specific cases, but there is also one general error case that will return 
{error, {Status,Body}}. This should probably be added later for better handling of errors.

My pull request is just a quick fix so that the errors actually return something and dont crash.