Describe the bug
When httpSafeOrigin is set in config.js, httpSafePort is not initialized properly in env.js.

Where did it happen?
I am packaging CryptPad for Cloudron. Found this when making the package.

To Reproduce
Have a config.js like below:

    httpSafeOrigin: `https://some.domain.com`,
    httpSafePort: 3001,

CryptPad does not listen on port 3001 as expected from above config.

Expected behavior
httpSafePort must be loaded from config.