CRM-13101 fix typo in widget css.

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* CRM-13101: Typo in contribution widget generated css for .crm-amounts
  http://issues.civicrm.org/jira/browse/CRM-13101

templates/CRM/Contribute/Page/Widget.tpl

@@ -25,7 +25,7 @@
     .crm-contribute-widget .crm-amounts {
         height:1em;
         margin:.8em 0px;
-        fon-size:13px;
+        font-size:13px;
     }
     .crm-contribute-widget .crm-amount-low {
         float:left;