http2: remove duplicate words in comments

PR-URL: nodejs#17939
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Jon Moss <me@jonathanmoss.me>
Reviewed-By: James M Snell <jasnell@gmail.com>

lib/internal/http2/core.js

@@ -364,7 +364,7 @@ function onFrameError(id, type, code) {
 
 // Receiving a GOAWAY frame from the connected peer is a signal that no
 // new streams should be created. If the code === NGHTTP2_NO_ERROR, we
-// are going to send our our close, but allow existing frames to close
+// are going to send our close, but allow existing frames to close
 // normally. If code !== NGHTTP2_NO_ERROR, we are going to send our own
 // close using the same code then destroy the session with an error.
 // The goaway event will be emitted on next tick.
@@ -419,7 +419,7 @@ function requestOnConnect(headers, options) {
   if (session.destroyed)
     return;
 
-  // If the session was closed while waiting for for the connect, destroy
+  // If the session was closed while waiting for the connect, destroy
   // the stream and do not continue with the request.
   if (session.closed) {
     const err = new errors.Error('ERR_HTTP2_GOAWAY_SESSION');