text: Bump up the preferred height

Instead of returning a sub-pixel height round up the preferred height to
the nearest integral value that is not less than the size reported by
Pango, once converted in pixels.

clutter/clutter-text.c

@@ -1853,7 +1853,7 @@ clutter_text_get_preferred_height (ClutterActor *self,
        * the height accordingly
        */
       logical_height = logical_rect.y + logical_rect.height;
-      layout_height = (gfloat) logical_height / 1024.0f;
+      layout_height = ceilf ((gfloat) logical_height / 1024.0f + 0.5);
 
       if (min_height_p)
         {