Hello!
You can either use the OpenVPN version packaged with Eddie, Hummingbird, or another version, as you prefer.
To change OpenVPN version selected by Eddie, please install in your system the OpenVPN version you prefer; then, run Eddie and from its main window select "Preferences" > "Advanced". Beside the "OpenVPN custom path" field please click the file requester symbol to navigate through your file system and choose the proper OpenVPN binary file. Finally click "Save". Alternatively just type in the field the binary name with the complete, absolute path, and click "Save".
Kind regards