fix(api/service-util): Fix scoped format compilation error

ref:
rust-lang/rust#64960
https://users.rust-lang.org/t/absolutely-massive-error-with-async-and-tokio-spawn/33290/3

Author: gakonst

crates/interledger-api/src/http_retry.rs

@@ -50,6 +50,8 @@ impl Client {
         // If the account is not found on the peer's connector, the
         // retry logic will not get triggered. When the counterparty
         // tries to add the account, they will complete the handshake.
+
+        let msg = format!("[Engine: {}, Account: {}]", engine_url, id);
         let res = FutureRetry::new(
             move || {
                 client
@@ -60,7 +62,7 @@ impl Client {
             },
             IoHandler::new(
                 self.max_retries,
-                format!("[Engine: {}, Account: {}]", engine_url, id),
+                msg,
             ),
         )
         .await?;

crates/interledger-service-util/src/exchange_rate_providers/cryptocompare.rs

@@ -51,13 +51,12 @@ pub async fn query_cryptocompare(
     client: &Client,
     api_key: &SecretString,
 ) -> Result<HashMap<String, f64>, ()> {
+    // ref: https://github.com/rust-lang/rust/pull/64856
+    let header = format!("Apikey {}", api_key.expose_secret()).to_string();
     let res = client
         .get(CRYPTOCOMPARE_URL.clone())
         // TODO don't copy the api key on every request
-        .header(
-            "Authorization",
-            format!("Apikey {}", api_key.expose_secret()).as_str(),
-        )
+        .header("Authorization", header)
         .send()
         .map_err(|err| {
             error!(

crates/interledger-service-util/src/exchange_rates_service.rs

@@ -258,11 +258,11 @@ where
         );
         let interval = async move {
             let mut interval = tokio::time::interval(interval);
-            while let _ = interval.tick().await {
+            loop {
+                interval.tick().await;
                 // Ignore errors so that they don't cause the Interval to stop
                 let _ = self.update_rates().await;
             }
-            Ok::<(), ()>(())
         };
         tokio::spawn(interval);
     }