align .ui-progressbar-value's content in the center

Author: nyordanov

themes/base/jquery.ui.progressbar.css

@@ -8,4 +8,4 @@
  * http://docs.jquery.com/UI/Progressbar#theming
  */
 .ui-progressbar { height:2em; text-align: left; }
-.ui-progressbar .ui-progressbar-value {margin: -1px; height:100%; }
+.ui-progressbar .ui-progressbar-value {margin: -1px; height:100%; text-align: center}