CRM-12243 Replaced loop on locales with {localize} tag.

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* CRM-12243: Beta 4 upgrade fails with duplicate column error if site was originally installed as a 4.3 site
  http://issues.civicrm.org/jira/browse/CRM-12243

CRM/Upgrade/Incremental/sql/4.3.beta5.mysql.tpl

 -- CRM-12142
 -- Populate default text for premiums_nothankyou_label
-{if !$multilingual}
-  UPDATE `civicrm_premiums` SET premiums_nothankyou_label = '{ts escape="sql"}No thank-you{/ts}';
-{else}
-  {foreach from=$locales item=locale}
-    UPDATE `civicrm_premiums` SET premiums_nothankyou_label_{$locale} = '{ts escape="sql"}No thank-you{/ts}';	   
-  {/foreach}
-{/if}
+UPDATE `civicrm_premiums` SET {localize field="premiums_nothankyou_label"}premiums_nothankyou_label = '{ts escape="sql"}No thank-you{/ts}'{/localize};
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