CircleCI: Don't update modules from upstream and use the commited hashes instead

Summary:
`--remote` updates submodules from upstream. This used to be ok because we used to be building against master which is almost always in sync with the remote thanks to shipit. On the other hand, this broke the release branch because some breaking changes landed in upstream.

This diff stops fetching from upstream in circle CI and uses the committed hashes in the repo instead.

Reviewed By: AhmedSoliman

Differential Revision: D17365456

fbshipit-source-id: 920538c45b34c670952c620dac151462acfa859b

Author: MohamedBassem

.circleci/config.yml

@@ -18,7 +18,7 @@ jobs:
       - run: apt-get install -y ca-certificates doxygen $(cat logdevice/build_tools/ubuntu.deps)
       - run: git reset --hard HEAD
       - run: git submodule sync
-      - run: git submodule update --init --recursive --remote
+      - run: git submodule update --init --recursive
       - run:
           name: Build LogDevice
           command: |