Fix metrics http server error messages (#1946)

## Issue Addressed

- Resolves #1945

## Proposed Changes

- As per #1945, fix a log message from the metrics server that was falsely claiming to be from the api server.
- Ensure successful api request logs are published to debug, not trace. This is something I've wanted to do for a while.

## Additional Info

NA

beacon_node/http_api/src/lib.rs

@@ -26,7 +26,7 @@ use lighthouse_version::version_with_platform;
 use network::NetworkMessage;
 use parking_lot::Mutex;
 use serde::{Deserialize, Serialize};
-use slog::{crit, error, info, trace, warn, Logger};
+use slog::{crit, debug, error, info, warn, Logger};
 use slot_clock::SlotClock;
 use ssz::Encode;
 use state_id::StateId;
@@ -116,7 +116,7 @@ pub fn slog_logging(
                     || status == StatusCode::NOT_FOUND
                     || status == StatusCode::PARTIAL_CONTENT =>
             {
-                trace!(
+                debug!(
                     log,
                     "Processed HTTP API request";
                     "elapsed" => format!("{:?}", info.elapsed()),