fix oss build failure due undefined symbol in folly
fix oss build failure due undefined symbol in folly

Summary: Fix for the issue https://github.com/facebookincubator/mvfst/issues/22

Reviewed By: mingtaoy

Differential Revision: D15709201

fbshipit-source-id: 474a4af4d08f631dbf294210181b13e582c972eb

facebookincubator/mvfst,facebookincubator/mvfst,facebookincubator/mvfst,facebookincubator/mvfst,facebookincubator/mvfst