CRM-12243 check if premiums_nothankyou_label column exists before adding it. Move update sql statement to beta5 mysql.

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

----------------------------------------
* 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
Merge pull request #274 from davecivicrm/CRM-12243

CRM-12243 check if premiums_nothankyou_label column exists before adding...