Workaround import mishmash in %check
    
    The namespace sphinxcontrib package made this problematic,
    because the package in $pwd was not namespace, but regular.
    
    Alternatively, sphinxcontrib/__init__.py could have been deleted,
    but not in %prep, because the package does not install without it.
    
    This solution makes sure we are testing what we are shipping.
    
    Fixes https://bugzilla.redhat.com/show_bug.cgi?id=1733681