h:selectOneRadio can't render HTML.NBSP_ENTITY before start label text

One test that comes from tck does not allow to put a HTML.NBSP_ENTITY before start label text for a select one radio. It is known that do not render this stuff could cause a checkbox be rendered too close to the text (see TOMAHAWK-1395), but note here we are taking about a radio button. Anyway, we have to replace render this text with a space in order to pass a tck test.