message: [tests] disconnect_ban: use wait_until instead of sleep
  Github-Pull:
  Rebased-From:
diff: #
  # Test node handling
  #
  -import time
  import urllib.parse
  +from test_framework.mininode import wait_until
  from test_framework.test_framework import BitcoinTestFramework
  from test_framework.util import (assert_equal,
  assert_raises_jsonrpc,
  @@ -35,7 +35,7 @@ class NodeHandlingTest(BitcoinTestFramework):
  ###########################
  assert_equal(len(self.nodes[1].getpeerinfo()), 2) # node1 should have 2 connections to node0 at this point
  self.nodes[1].setban("127.0.0.1", "add")
  - time.sleep(3) # wait till the nodes are disconected
  + wait_until(lambda: len(self.nodes[1].getpeerinfo()) == 0)
  assert_equal(len(self.nodes[1].getpeerinfo()), 0) # all nodes must be disconnected at this point
  assert_equal(len(self.nodes[1].listbanned()), 1)
  self.nodes[1].clearbanned()
  @@ -61,10 +61,9 @@ class NodeHandlingTest(BitcoinTestFramework):
  self.nodes[1].setban("192.168.0.1", "add", 1) # ban for 1 seconds
  self.nodes[1].setban("2001:4d48:ac57:400:cacf:e9ff:fe1d:9c63/19", "add", 1000) # ban for 1000 seconds
  listBeforeShutdown = self.nodes[1].listbanned()
  - assert_equal("192.168.0.1/32", listBeforeShutdown[2]['address']) # must be here
  - time.sleep(2) # make 100% sure we expired 192.168.0.1 node time
  + assert_equal("192.168.0.1/32", listBeforeShutdown[2]['address'])
  + wait_until(lambda: len(self.nodes[1].listbanned()) == 3)
  - # stop node
  stop_node(self.nodes[1], 1)
  self.nodes[1] = start_node(1, self.options.tmpdir)
  @@ -82,7 +81,7 @@ class NodeHandlingTest(BitcoinTestFramework):
  ###########################
  url = urllib.parse.urlparse(self.nodes[1].url)
  self.nodes[0].disconnectnode(url.hostname + ":" + str(p2p_port(1)))
  - time.sleep(2) # disconnecting a node needs a little bit of time
  + wait_until(lambda: len(self.nodes[0].getpeerinfo()) == 1)
  for node in self.nodes[0].getpeerinfo():
  assert(node['addr'] != url.hostname + ":" + str(p2p_port(1)))
  