9f9db39041 QA/mininode: Send all headers upfront in send_blocks_and_test to avoid sending an unconnected one (Luke Dashjr)
Pull request description:
While this doesn't currently trigger any problems, the network protocol does expect headers to be sent connectable in normal circumstances, and if too many are sent out of order will disconnect the peer.
ACKs for commit 9f9db3:
Tree-SHA512: 25b88718e4ba3d31aed2de7ece23fab9a0737fd6536c5e618ea8eb5a3a217dab0dffaebc4892df7993bcea7efb7c4fb5085fabebe99535b8f7fdde3c19df54ff