live-security: don't exclude realmd package
    
    Needed by anaconda. See [1].
    
    ```
    - package anaconda-28.22-1.fc28.x86_64 requires anaconda-core = 28.22-1.fc28, but none of the providers can be installed
    - nothing provides realmd needed by anaconda-core-28.22-1.fc28.x86_64.
    ```
    
    [1] https://pagure.io/dusty/failed-composes/issue/9#comment-495037
    
    Signed-off-by: Dusty Mabe <dusty@dustymabe.com>