Offchain: Disable http requests (#4188)

We don't use any http requests in the polkadot offchain workers.

node/service/Cargo.toml

@@ -24,6 +24,7 @@ sc-transaction-pool = { git = "https://github.com/paritytech/substrate", branch
 sc-sync-state-rpc = { git = "https://github.com/paritytech/substrate", branch = "master" }
 sc-keystore = { git = "https://github.com/paritytech/substrate", branch = "master" }
 sc-basic-authorship = { git = "https://github.com/paritytech/substrate", branch = "master" }
+sc-offchain = { git = "https://github.com/paritytech/substrate", branch = "master" }
 service = { package = "sc-service", git = "https://github.com/paritytech/substrate", branch = "master", default-features = false }
 telemetry = { package = "sc-telemetry", git = "https://github.com/paritytech/substrate", branch = "master" }
 

node/service/src/lib.rs

@@ -797,11 +797,21 @@ where
 		})?;
 
 	if config.offchain_worker.enabled {
-		let _ = service::build_offchain_workers(
-			&config,
-			task_manager.spawn_handle(),
+		let offchain_workers = Arc::new(sc_offchain::OffchainWorkers::new_with_options(
 			client.clone(),
-			network.clone(),
+			sc_offchain::OffchainWorkerOptions { enable_http_requests: false },
+		));
+
+		// Start the offchain workers to have
+		task_manager.spawn_handle().spawn(
+			"offchain-notifications",
+			sc_offchain::notification_future(
+				config.role.is_authority(),
+				client.clone(),
+				offchain_workers,
+				task_manager.spawn_handle().clone(),
+				network.clone(),
+			),
 		);
 	}