This cert has an invalid serial number - it is NULL rather than being an INTEGER.

The certificate data can be updated/regenerated with the
net/data/parse_certificate_unittest/regenerate_pem_from_ascii.py script.

#-----BEGIN SERIAL-----
    NULL {}
#-----END SERIAL-----

-----BEGIN CERTIFICATE-----
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
-----END CERTIFICATE-----

ERROR: Failed reading serialNumber
ERROR: Failed parsing TBSCertificate

-----BEGIN ERRORS-----
RVJST1I6IEZhaWxlZCByZWFkaW5nIHNlcmlhbE51bWJlcgpFUlJPUjogRmFpbGVkIHBhcnNpbmcgVEJTQ2VydGlmaWNhdGUK
-----END ERRORS-----