fix onlink to be an attribute
fix onlink to be an attribute

KeyproOy/OWSLib,bird-house/OWSLib,datagovuk/OWSLib,mbertrand/OWSLib,gfusca/OWSLib,jaygoldfinch/OWSLib,datagovuk/OWSLib,Jenselme/OWSLib,datagovuk/OWSLib,kwilcox/OWSLib,menegon/OWSLib,QuLogic/OWSLib,kalxas/OWSLib,jaygoldfinch/OWSLib,tomkralidis/OWSLib,robmcmullen/OWSLib,jachym/OWSLib,daf/OWSLib,dblodgett-usgs/OWSLib,JuergenWeichand/OWSLib,daf/OWSLib,daf/OWSLib,geographika/OWSLib,b-cube/OWSLib,ocefpaf/OWSLib,geopython/OWSLib