Manual:$wgCopyUploadAsyncTimeout

Details
The HTTP timeout (in seconds) to use when downloading the file for an asynchronous upload-by-URL request. This could be useful since when fetching large files via the job queue, you may want a different timeout, especially because there is no HTTP request being kept alive.

By default, or when set to false, MediaWiki falls back to the value of. If that is also false, the value of is used.