Elytron Tool encrypt command incorrectly overwrites CLI script

When the filesystem-realm-encrypt command of Elytron Tool completes, it generates a CLI script to add the new realm to WildFly. If the script would overwrite a file, the user is prompted to confirm they want to overwrite the file.

The current logic is flipped, so if a user answers y, then the script will append to the existing file, while answering n will truncate the file to overwrite it.