GitHub issue https://github.com/phax/phive-rules/issues/21

Original request from GitHub user @janwytze

When I get the PEPPOL-EN16931-R120 error, no text is returned:

https://github.com/phax/phive-rules/blob/b34d05dbdbb1b51262e8733f7440e1487eb40f42/phive-rules-xrechnung/src/main/resources/external/schematron/3.0.2/XRechnung-UBL-validation.xslt#L636

In the Mustang schematron I do see the text:

https://github.com/ZUGFeRD/mustangproject/blob/300461a5da07be0b0da0fb58ae50e789611f3be5/validator/src/main/resources/xslt/XR_30/XRechnung-UBL-validation.xslt#L710