HPCC-12567 Remove ASCII option from XML Spray

Fixes HPCC-12567

Signed-off-by: Gordon Smith <gordon.smith@lexisnexis.com>
Merge pull request #6633 from GordonSmith/HPCC-12567

HPCC-12567 Remove ASCII option from XML Spray

Reviewed-By: Miguel Vazquez <miguel.vazquez@lexisnexis.com>
Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>