Allow having a dedicated loggin configuration for the git hooks
    
    Pagure's logging can now be configured in ``LOGGING`` as before
    for both the web application as well as the git hooks.
    But if needed/desired, the git hooks can have a different logging
    configuration that will be specified in ``LOGGING_GIT_HOOKS``.
    If ``LOGGING_GIT_HOOKS`` is not specified (default) the ``LOGGING``
    configuration will be used instead.
    
    Signed-off-by: Pierre-Yves Chibon <pingou@pingoured.fr>