Trivial fix to HIBC input validation
Trivial fix to HIBC input validation

bwipp/postscriptbarcode,bwipp/postscriptbarcode,bwipp/postscriptbarcode,bwipp/postscriptbarcode,bwipp/postscriptbarcode,bwipp/postscriptbarcode,bwipp/postscriptbarcode,bwipp/postscriptbarcode