Investigate timeouts with the node's API

[Leo-Besancon]

The transfers_indexer sometimes panics with:

thread 'tokio-runtime-worker' panicked at src/main.rs:144:63:
called `Result::unwrap()` on an `Err` value: ErrorObject { code: ServerError(-32080), message: "Request timeout", data: None }
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

Notes:

• The timeout on the node's API is set to 5 seconds on our instance,
• Manually querying the node (after the bug has been resolved..) shows no lag at all
• Monitoring does not seem to show anything unusual.