revert back to ?'s for error propigation

examples/fairing.rs

@@ -27,8 +27,7 @@ async fn main() -> Result<(), Box<dyn Error>> {
         .mount("/", routes![cors])
         .attach(cors)
         .launch()
-        .await
-        .ok();
+        .await?;
 
     Ok(())
 }

examples/guard.rs

@@ -55,8 +55,7 @@ async fn main() -> Result<(), Box<dyn Error>> {
         .mount("/", routes![manual, manual_options])
         .manage(cors)
         .launch()
-        .await
-        .ok();
+        .await?;
 
     Ok(())
 }