don't shrink for Exceptions

[Stefanqn]

e.g. in my current use case, a entity is created and saved to mongoDB. If mongoDB is unavailable, a MongoTimeoutException is thrown (after 5 sec) and the test shrinks continues shrinking the entity for a long time.

It would be great, if I could disable shrinking for certain Exceptions (like MongoTimeoutException) or disable it by default and just allow shrinking for e.g. TestFailedExceptions.