doc: correct entry for electron v4.0.4

`abi_version_registry.json` incorrectly specified that electron v4.0.4
used `NODE_MODULE_VERSION` 64, but in fact it uses 69.

See:

* https://github.com/electron/electron/pull/16687
* https://github.com/electron/electron/releases/tag/v4.0.4
* https://github.com/lgeiger/node-abi/commit/9e4c1a63e63f8994cc2f5e3efee43785c9eb1c8f

PR-URL: https://github.com/nodejs/node/pull/27394


Reviewed-By: Myles Borins <myles.borins@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>