message: Add missing until param for enumeration elements
diff: </xs:sequence>
  <xs:attribute type="xs:string" name="name" use="optional"/>
  <xs:attribute type="xs:float" name="since" use="optional"/>
  + <xs:attribute type="xs:float" name="until" use="optional"/>
  <xs:attribute type="xs:string" name="internal_name" use="optional"/>
  <xs:attribute type="xs:int" name="value" use="optional"/>
  <xs:attribute type="xs:string" name="rootscreen" use="optional"/>
  