store intercept to set_proxy on requests

tests/support/server.rs

@@ -52,7 +52,8 @@ pub fn spawn(txns: Vec<Txn>) -> Server {
             let mut n = 0;
             while n < expected.len() {
                 match socket.read(&mut buf[n..]) {
-                    Ok(0) | Err(_) => break,
+                    Ok(0) => break,
+                    Err(e) => panic!(e),
                     Ok(nread) => n += nread,
                 }
             }