Issue 50370 - CleanAllRUV task crashing during server shutdown
    
    Description:
    Added test case to check if CleanAllRUV task didn't crash during server shutdown.
    
    This code is not in a mergeable state yet.
    I need review, if my steps are correct, because it is a timing issue to reproduce the bug.
    
    https://pagure.io/389-ds-base/issue/50370
    
    Reviewed by: mreynolds (Thanks!)