message: [test] Extract sending an addr message into a helper
  Also reduces mocktime to prevent idle disconnects
diff: @@ -58,6 +58,14 @@ class AddrTest(BitcoinTestFramework):
  msg.addrs = addrs
  return msg
  + def send_addr_msg(self, source, msg, receivers):
  + source.send_and_ping(msg)
  + # pop m_next_addr_send timer
  + self.mocktime += 5 * 60
  + self.nodes[0].setmocktime(self.mocktime)
  + for peer in receivers:
  + peer.sync_with_ping()
  +
  def oversized_addr_test(self):
  self.log.info('Send an addr message that is too large')
  addr_source = self.nodes[0].add_p2p_connection(P2PInterface())
  @@ -86,11 +94,7 @@ class AddrTest(BitcoinTestFramework):
  'received: addr (301 bytes) peer=1',
  ]
  ):
  - addr_source.send_and_ping(msg)
  - self.mocktime += 30 * 60
  - self.nodes[0].setmocktime(self.mocktime)
  - for receiver in receivers:
  - receiver.sync_with_ping()
  + self.send_addr_msg(addr_source, msg, receivers)
  total_ipv4_received = sum(r.num_ipv4_received for r in receivers)
  