Fix "IOBufQueue: chain length not cached" exception

Summary:
We create `inputQueueCopy` without the
`folly::IOBufQueue::cacheChainLength()` option, then assign it to `inputQueue_`
and use `.chainLength()`.

This diff fixes `inputQueueCopy` to be created with a cached length.

Reviewed By: ckwalsh

Differential Revision: D2908010

fb-gh-sync-id: 25f1a9ededa5d8341535be23a89d0fd971db85d5

thrift/lib/cpp2/async/ProtectionHandler.cpp

@@ -67,7 +67,8 @@ void ProtectionHandler::read(Context* ctx, folly::IOBufQueue& q) {
             // If decryption fails, we try to read again without decrypting.
             // The copy is necessary since a decryption attempt modifies the
             // queue.
-            folly::IOBufQueue inputQueueCopy;
+            folly::IOBufQueue inputQueueCopy(
+                folly::IOBufQueue::cacheChainLength());
             auto copyBuf = inputQueue_.front()->clone();
             copyBuf->unshare();
             inputQueueCopy.append(std::move(copyBuf));