Add lang="en" tag to international version pref labels

[janelomax]

In http://purl.obolibrary.org/obo/hp/hp-international.owl the class labels all have explicit lang tags except for the English one e.g.

<rdfs:label xml:lang="fr">Anomalie phénotypique</rdfs:label>
        <rdfs:label xml:lang="es">Anomalía fenotípica</rdfs:label>
        <rdfs:label xml:lang="tr">Fenotipik anormallik</rdfs:label>
        <rdfs:label xml:lang="nl">Fenotypische abnormaliteit</rdfs:label>
        <rdfs:label xml:lang="cs">Fenotypová abnormalita</rdfs:label>
        <rdfs:label>Phenotypic abnormality</rdfs:label>

would it be possible to also have lang="en" tag added to the English labels please?