Allow overriding the path in rake security:generate_token
The path is currently hardcoded to Rails.root/config/initializers/local_secret_token.rb. In production setups we want to store this in /etc/foreman with a symlink Rails.root/config/initializers/local_secret_token.rb so there's no state in /usr. https://github.com/theforeman/foreman-packaging/pull/2143 works around this by creating the file, moving it and then ensuring the symlink. This is cumbersome and making the path configurable would avoid one step.