Check if FairDetector::Initialize() is called twice

[fuhlig1]

When running a transport simulation the Initialize() function of FairDetector is called twice. Once it is called from FairMCApplication, the second time it is called from TVirtualMC directly. The second call was added implicitly with the code changes and is the new default way to call Initialize() function of FairDetector.

Add a new test or change an existing test which crashes when the Initilize() function is called twice.

[ChristianTackeGSI]

I have no idea, why the linked PR did not close this one. Closing.