tus: reduce chunk size (25MB -> 10MB)

With the throughput tweaks at the backend, it seems like the number of "file is locked" errors have reduced.

The next thing to try is to reduce the chunk size, hoping that file writes would be faster, reducing the lock duration from causing a timeout.

web/setup/publish-v2.js

@@ -7,7 +7,7 @@ import { LBRY_WEB_PUBLISH_API_V2 } from 'config';
 
 const RESUMABLE_ENDPOINT = LBRY_WEB_PUBLISH_API_V2;
 const RESUMABLE_ENDPOINT_METHOD = 'publish';
-const UPLOAD_CHUNK_SIZE_BYTE = 25 * 1024 * 1024;
+const UPLOAD_CHUNK_SIZE_BYTE = 10 * 1024 * 1024;
 
 const STATUS_CONFLICT = 409;
 const STATUS_LOCKED = 423;