[repository schema] Typo in annotation of messageIdKey

[kleihan]

Text should say "scenario id" and not "scenario name".

        <xs:key name="messageIdKey">
            <xs:annotation>
                <xs:documentation>Combination of message id and scenario name must be
                    unique</xs:documentation>
            </xs:annotation>
            <xs:selector xpath="fixr:message"/>
            <xs:field xpath="@id"/>
            <xs:field xpath="@scenarioId"/>
        </xs:key>

[kleihan]

Implemented in RC1