Fix an oversight with helper functions using validate_scalar().
Fix an oversight with helper functions using validate_scalar().

artburkart/voluptuous,tuukkamustonen/voluptuous,natlownes/voluptuous,tuukkamustonen/voluptuous,SimplyKnownAsG/voluptuous,divanovGH/voluptuous,alecthomas/voluptuous,alecthomas/voluptuous,jmwri/voluptuous,SimplyKnownAsG/voluptuous