CRM-14989 don't set alreadyInvoked as true till yr actually invoking
introduced in 45d8c9c when the preceding conditions were moved

----------------------------------------
* CRM-14989: WordPress plugins that process the_content cause prevent CiviCRM invoke
  https://issues.civicrm.org/jira/browse/CRM-14989
Merge pull request #47 from agh1/CRM-14989

CRM-14989 WordPress plugins that process the_content cause prevent CiviCRM invoke