message: QA/mininode: Send all headers upfront in send_blocks_and_test to avoid sending an unconnected one
diff: @@ -534,7 +534,7 @@ class P2PDataStore(P2PInterface):
  for b in blocks:
  self.send_message(msg_block(block=b))
  else:
  - self.send_message(msg_headers([CBlockHeader(blocks[-1])]))
  + self.send_message(msg_headers([CBlockHeader(block) for block in blocks]))
  wait_until(lambda: blocks[-1].sha256 in self.getdata_requests, timeout=timeout, lock=mininode_lock)
  if expect_disconnect:
  