Only paint a separator if the text is NULL, rather than also doing it if

Only paint a separator if the text is NULL, rather than also doing it if

2003-10-29  Federico Mena Quintero  <federico@ximian.com>

	* gtk/gtkcellrendererseptext.c
	(gtk_cell_renderer_sep_text_render): Only paint a separator if the
	text is NULL, rather than also doing it if it is an empty string.