clients/editor.c: Draw cursor at correct verical position

With this patch, the editor cursor now moves up and down correctly
instead of having the top part stuck on the first line.
diff --git a/clients/editor.c b/clients/editor.c
index 5e8ae8e..7e69403 100644
--- a/clients/editor.c
+++ b/clients/editor.c
@@ -946,8 +946,8 @@
 				    &cursor_pos, NULL);
 
 	cairo_set_line_width(cr, 1.0);
-	cairo_move_to(cr, PANGO_PIXELS(cursor_pos.x), PANGO_PIXELS(extents.height) + 2);
-	cairo_line_to(cr, PANGO_PIXELS(cursor_pos.x), - 2);
+	cairo_move_to(cr, PANGO_PIXELS(cursor_pos.x), PANGO_PIXELS(cursor_pos.y));
+	cairo_line_to(cr, PANGO_PIXELS(cursor_pos.x), PANGO_PIXELS(cursor_pos.y) + PANGO_PIXELS(cursor_pos.height));
 	cairo_stroke(cr);
 }