Misc/NEWS.d/next/Library/2018-05-28-22-49-59.bpo-33674.6LFFj7.rst

Fix a race condition in SSLProtocol.connection_made() of asyncio.sslproto:
start immediately the handshake instead of using call_soon(). Previously,
data_received() could be called before the handshake started, causing the
handshake to hang or fail.