No, once you've flagged to close for any reason there's no going back.

Here's the [feature request][1] to allow you to change that vote (it's currently the number one status-declined feature request on Meta).

Here's one to allow you to [swap close reasons][2].


  [1]: http://meta.stackexchange.com/questions/915/can-we-have-the-ability-to-rescind-a-close-vote-before-it-closes
  [2]: http://meta.stackexchange.com/questions/863/ability-to-change-close-reason-before-it-gets-closed