Remove onselect attribute from SELECT elements

According to JSF 2.3 spec issue https://github.com/javaee/javaserverfaces-spec/issues/1113 we need to remove the onselect attribute from h:selectOneMenu/h:selectManyMenu/h:selectOneListbox/h:selectManyListbox.

I have tested on Mojarra 2.3 and they don't actually render the onselect attribute.