invalid OnlineResource element returned by WMS 1.3.0 GetCapabilities

[mtCarto]

Using GeoTools 27-Snapshot to access a WMS 1.3.0 service endpoint fails to parse the GetCapabilities document returned by the geotrellis-server. The culprit is a blank OnlineResource element in the service metadata.

        <Name>WMS</Name>
        <Title>elevation</Title>
        <KeywordList>
            <Keyword>HRDEM</Keyword>
            <Keyword>DEM</Keyword>
            <Keyword>DTM</Keyword>
            <Keyword>DSM</Keyword>
            <Keyword>MNEHR</Keyword>
            <Keyword>MNE</Keyword>
            <Keyword>MNS</Keyword>
            <Keyword>MNT</Keyword>
        </KeywordList>
        <OnlineResource/>

Is this a bug with the server not populating the OnlineResource block? Could that element be omitted if it has no values, since the WMS spec doesn't say its required but states it may be used to refer to the service providers site.