try to fix read_until and writed more debug logs

src/server.rs

@@ -482,7 +482,11 @@ fn read_until(stream: &mut impl BufRead, delimiter: &[u8]) -> Option<Vec<u8>> {
 
     loop {
         let mut buf = Vec::new();
-        stream.read_until(last_byte, &mut buf).ok()?;
+        let buf_len = stream.read_until(last_byte, &mut buf).ok()?;
+        debug!("read buf len until {} {:?}", buf_len, String::from_utf8_lossy(&buf));
+        if buf_len == 0 {
+            return None
+        }
         data.append(&mut buf);
         if data.ends_with(delimiter) {
             break;