Refactor error management in API part

src/rpc/membership.rs

@@ -373,7 +373,7 @@ impl System {
 					Message::AdvertiseNodesUp(adv) => self2.handle_advertise_nodes_up(&adv).await,
 					Message::AdvertiseConfig(adv) => self2.handle_advertise_config(&adv).await,
 
-					_ => Err(Error::BadRequest(format!("Unexpected RPC message"))),
+					_ => Err(Error::BadRPC(format!("Unexpected RPC message"))),
 				}
 			}
 		});

src/rpc/rpc_server.rs

@@ -61,7 +61,10 @@ where
 			let err_str = format!("{}", e);
 			let rep_bytes = rmp_to_vec_all_named::<Result<M, String>>(&Err(err_str))?;
 			let mut err_response = Response::new(Body::from(rep_bytes));
-			*err_response.status_mut() = e.http_status_code();
+			*err_response.status_mut() = match e {
+				Error::BadRPC(_) => StatusCode::BAD_REQUEST,
+				_ => StatusCode::INTERNAL_SERVER_ERROR,
+			};
 			warn!(
 				"RPC error ({}): {} ({} ms)",
 				name,