Fix AddressSanitizer: heap-buffer-overflow in ValidateCanonicalTime()
Fix AddressSanitizer: heap-buffer-overflow in ValidateCanonicalTime()

BUG=pdfium:378
R=tsepez@chromium.org

Review URL: https://codereview.chromium.org/1652933002 .

DrAlexx/pdfium,andoma/pdfium,DrAlexx/pdfium,andoma/pdfium,DrAlexx/pdfium,andoma/pdfium,DrAlexx/pdfium,andoma/pdfium