plugins: fix restorecon "then" text
    
    In case a syscall fails due to insufficient permissions to parent
    directory of target object, PATH record provided by audit will contain
    path to the target object of the syscall (not the parent directory).
    Unfortunately I haven't found a way to distinguish this case (let alone
    determine the parent directory causing the denial).
    
    Update restorecon plugin "then" text to let the user know that the
    provided command may not help (since restorecon is called on the wrong
    object).
    
    fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1332097
    
    Signed-off-by: Vit Mojzis <vmojzis@redhat.com>