removed global cleanup

[TyrionWarMage]

Fixed a misunderstanding concerning the default step. I assumed, this is only triggered in case the import is finished and can therefore be used for cleanup tasks. However, i found there are code paths that do not return a valid next step and therefore trigger the default step. This concerns #138.

This PR moves the password cleanup into the import step, after the FinTS tasks are done. In case of abnormal exist, the cache will be cleared after 600 seconds on the next request.