Fix sample sheet schema validation reporting
Fix sample sheet schema validation reporting

* Don't stain the terminal red
* Print the top-level message in case causingExceptions is empty.
ewels/NGI-RNAseq,ewels/NGI-RNAseq,ewels/NGI-RNAseq,ewels/NGI-RNAseq,ewels/NGI-RNAseq