Issue 16 - Reset InstScriptsEnabled argument during the init
    
    Bug description: the InstScriptsEnabled argument is reused for the next
    instance setups and it affects script directory creation.
    
    Fix description: Reset the InstScriptsEnabled argument before instance
    setup.
    
    https://pagure.io/lib389/issue/16
    
    Reviewed by: wibrown (Thanks!)