Ignore listen attribute of <graphics> for type network listens
    
    Commit 6992994 started filling the listen attribute
    of the parent <graphics> elements from type='network' listens.
    
    When this XML is passed to UpdateDevice, parsing fails:
    XML error: graphics listen attribute 10.20.30.40 must match
    address attribute of first listen element (found none)
    
    Ignore the address in the parent <graphics> attribute
    when no type='address' listens are found,
    the same we ignore the address for the <listen> subelements
    when parsing inactive XML.