Update https.js

Co-authored-by: Joyee Cheung <joyeec9h3@gmail.com>

Author: mcollina

lib/https.js

@@ -244,7 +244,7 @@ function establishTunnel(agent, socket, options, tunnelConfig, afterSocket) {
   // clean up the socket and return an error. Otherwise we establish the tunnel.
   let buffer;
   function onProxyData(chunk) {
-    debug('onProxyData', chunk.toString());
+    debug('onProxyData', chunk.length);
     buffer = buffer === undefined ? chunk :
       Buffer.concat([buffer, chunk], buffer.length + chunk.length);
     const headerEndIndex = buffer.indexOf('\r\n\r\n');