dojson: corrigendum

[kaplun]

https://sentry.cern.ch/inspire-sentry/inspire-labs/group/822798/

Records with material corrigendum:

<datafield tag="024" ind1="7" ind2=" ">
    <subfield code="2">DOI</subfield>
    <subfield code="q">Corrigendum</subfield>
    <subfield code="9">bibmatch</subfield>
    <subfield code="a">10.1016/j.physletb.2014.05.010</subfield>
</datafield>

should be conflated into erratum (see also inspirehep/inspire-schemas#195 (comment))

[jacquerie]

As mentioned by @michamos in https://sentry.cern.ch/inspire-sentry/inspire-labs/group/822798/, no need to handle this in DoJSON as this was affecting exactly two records, which were since corrected.