OP-805 - GCS Options dialog crash. (bugfix done by filnet)

Solves: "It is possible to make GCS crash by repeatedly and randomly cloning/deleting configurations and closing the Options dialog."

http://jira.openpilot.org/browse/OP-805
http://git.openpilot.org/cru/OPReview-380

I could reproduce the crash, and can confirm the bugfix works on OSX 10.8.