CORS errror when uploading a file exceeding the limit
Hello and thank you for your great work on this library. 

I use it 
- with express-graphql on the server 
- with vuejs on the client (with graphql-upload-client). 

Everything works fine except one thing: 
- if we try to upload a file exceeding the limit defined by `maxFileSize` the error message on `localhost` is correct: `File truncated as it exceeds the 3000000 byte size limit.`. But when I do the same on a remote VPS, the error is 

```
POST https://api.my-app.tld/ 413
Access to XMLHttpRequest at 'https://api.my-app.tld/' from origin 'https://my-app.tld' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.
```

I tried to set the CORS `Access-Control-Allow-Origin` on the server to different values (including '*'), with no success. 

Why is this error message different from `localhost`? 
How to control this error message?

Thank you

* * *

The repos are here: 
- api: https://github.com/MTES-MCT/camino-api/blob/80ed1de9bd50b70ded6438feca063e7ba8b3c154/src/server/middleware-upload.ts
- ui: https://github.com/MTES-MCT/camino-ui/blob/f4b6d745e2aa3e45d5037c1369183c5eb9c1ce4e/src/api/_graphql-client.js#L38