--CRM-13446, fixed Upgrade code for fatal error if civicrm_financial_account.contact_id is NOT NULL by default.

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* CRM-13446: Add ON DELETE Options for constraints fails
  http://issues.civicrm.org/jira/browse/CRM-13446
Merge pull request #1693 from pradpnayak/CRM-13446

--CRM-13446, fixed Upgrade code for fatal error if civicrm_financial_acc...