Wrong dimensions in `condition` bits does not throw error

[sanjayankur31]

<neuroml xmlns="http://www.neuroml.org/schema/neuroml2"  xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.neuroml.org/schema/neuroml2 https://raw.github.com/NeuroML/NeuroML2/development/Schemas/NeuroML2/NeuroML_v2.3.1.xsd" id="kd3">
    <ionChannelHH id="kd3" species="K" conductance="10 pS">
        <annotation/>
        <gate id="n" instances="1" type="gateHHrates">
            <q10Settings type="q10ExpTemp" q10Factor="3" experimentalTemp="16 degC"/>
            <forwardRate type="HHNearlyExpLinearRate" rate="0.02 per_ms" midpoint="20 mV" scale="9 mV"/>
            <reverseRate type="HHNearlyExpLinearRate" rate="-0.002 per_ms" midpoint="20 mV" scale="-9 mV"/>
        </gate>
    </ionChannelHH>
    <ComponentType name="HHNearlyExpLinearRate" extends="baseHHRate" description="A HHExpLinearRate, but not quite">
        <Parameter name="scale" dimension="voltage"/>
        <Parameter name="midpoint" dimension="voltage"/>
        <Parameter name="rate" dimension="per_time"/>
        <Dynamics>
            <DerivedVariable name="x" dimension="voltage" value="(v - midpoint)"/>
            <ConditionalDerivedVariable name="r" dimension="per_time" exposure="r">
                <!-- the condition below should throw an error, the value bit should also throw an error, dimensions are wrong in both places -->
                <Case condition="x .neq. 0" value="rate * x/(1 - exp(0 - x/scale))"/>
                <Case value="rate"/>
            </ConditionalDerivedVariable>
        </Dynamics>
    </ComponentType>
</neuroml>