fallback to non-rsocket channel on timeout
fallback to non-rsocket channel on timeout

Summary:
The sandcastle tests use the -oss flavor of the eden server which
appears to never respond to requests on the rsocket enabled endpoint.

The sandcastle/buck flavor of the build uses the -oss flavor of the eden
server which is why the test failures only manifest there.

Reviewed By: strager

Differential Revision: D10080988

fbshipit-source-id: 0183acb97393ab66779ffaabddd89178b9a9d824

wez/watchman,facebook/watchman,wez/watchman,nodakai/watchman,nodakai/watchman,wez/watchman,nodakai/watchman,nodakai/watchman,nodakai/watchman,wez/watchman,nodakai/watchman,facebook/watchman,nodakai/watchman,nodakai/watchman,wez/watchman,facebook/watchman,facebook/watchman,wez/watchman,wez/watchman,nodakai/watchman,facebook/watchman,facebook/watchman,facebook/watchman,facebook/watchman,facebook/watchman,wez/watchman,wez/watchman