message: test: Wait for 'cmpctblock' in p2p_compactblocks when it is expected
  This is a more narrowly-construed wait which eliminates the possibility of the
  wait being triggered by other messages.
diff: @@ -299,12 +299,11 @@ class CompactBlocksTest(BitcoinTestFramework):
  block.rehash()
  # Wait until the block was announced (via compact blocks)
  - wait_until(test_node.received_block_announcement, timeout=30, lock=mininode_lock)
  + wait_until(lambda: "cmpctblock" in test_node.last_message, timeout=30, lock=mininode_lock)
  # Now fetch and check the compact block
  header_and_shortids = None
  with mininode_lock:
  - assert "cmpctblock" in test_node.last_message
  # Convert the on-the-wire representation to absolute indexes
  header_and_shortids = HeaderAndShortIDs(test_node.last_message["cmpctblock"].header_and_shortids)
  self.check_compactblock_construction_from_block(version, header_and_shortids, block_hash, block)
  @@ -314,12 +313,11 @@ class CompactBlocksTest(BitcoinTestFramework):
  inv = CInv(MSG_CMPCT_BLOCK, block_hash)
  test_node.send_message(msg_getdata([inv]))
  - wait_until(test_node.received_block_announcement, timeout=30, lock=mininode_lock)
  + wait_until(lambda: "cmpctblock" in test_node.last_message, timeout=30, lock=mininode_lock)
  # Now fetch and check the compact block
  header_and_shortids = None
  with mininode_lock:
  - assert "cmpctblock" in test_node.last_message
  # Convert the on-the-wire representation to absolute indexes
  header_and_shortids = HeaderAndShortIDs(test_node.last_message["cmpctblock"].header_and_shortids)
  self.check_compactblock_construction_from_block(version, header_and_shortids, block_hash, block)
  @@ -696,10 +694,9 @@ class CompactBlocksTest(BitcoinTestFramework):
  node.submitblock(ToHex(block))
  for l in listeners:
  - wait_until(lambda: l.received_block_announcement(), timeout=30, lock=mininode_lock)
  + wait_until(lambda: "cmpctblock" in l.last_message, timeout=30, lock=mininode_lock)
  with mininode_lock:
  for l in listeners:
  - assert "cmpctblock" in l.last_message
  l.last_message["cmpctblock"].header_and_shortids.header.calc_sha256()
  assert_equal(l.last_message["cmpctblock"].header_and_shortids.header.sha256, block.sha256)
  