Make test actually fail if the ratio is too big

Author: rklaehn

iroh/src/endpoint.rs

@@ -3273,6 +3273,7 @@ mod tests {
             dt1.as_secs_f64(),
             dt1.as_secs_f64() / (n as f64)
         );
+        assert!(dt0.as_secs_f64() / dt1.as_secs_f64() < 20.0);
         Ok(())
     }
 }