wrong result with stringifying

qs.stringify({ a: ['b', 'c'] }, { arrayFormat: 'comma' })
return a=b%2Cc

when it should return a=b,c

because parsing , as reserved character per RFC 3986 should split the array if we used a parser withcomma: true option
and %2C (percent encoded comma) should be treated normally as text character

related to : #336 pr