Fix undefined text on disabled Ora

[Fonger]

I'm using next.js and it use Ora to show building spinner.
However, on Travis CI, there is extra - undefined message because of undefined text.

- undefined
> Using external babel configuration
- undefined
> Location: "/xxxxxxxxxxxxx/babel.config.json"
- undefined
> Using external babel configuration
- undefined
> Location: "/xxxxxxxxxxxxx/.babelrc.js"
- undefined
Creating an optimized production build

Compiled successfully.

After this PR:

> Using external babel configuration
> Location: "/xxxxxxxxxxxxx/babel.config.json"
> Using external babel configuration
> Location: "/xxxxxxxxxxxxx/.babelrc.js"
Creating an optimized production build

Compiled successfully.