Merge #19552: test: fix intermittent failure in p2p_ibd_txrelay

12410b1feb80189061eb4a2b43421e53cbb758a8 test: fix intermittent p2p_ibd_txrelay race, add test_framework.py#wait_until (Jon Atack)

Pull request description:

  To fix these intermittent failures in Travis CI.
  ```
  162/163 - p2p_ibd_txrelay.py failed, Duration: 2 s

  stdout:
  2020-07-19T05:44:17.213000Z TestFramework (INFO):
      Check that nodes set minfilter to MAX_MONEY while still in IBD
  2020-07-19T05:44:17.216000Z TestFramework (ERROR): Assertion failed
  Traceback (most recent call last):
    File "/Users/travis/build/bitcoin/bitcoin/ci/scratch/build/bitcoin-x86_64-apple-darwin16/test/functional/test_framework/test_framework.py", line 117, in main
      self.run_test()
    File "/Users/travis/build/bitcoin/bitcoin/ci/scratch/build/bitcoin-x86_64-apple-darwin16/test/functional/p2p_ibd_txrelay.py", line 30, in run_test
      assert_equal(conn_info['minfeefilter'], MAX_FEE_FILTER)
    File "/Users/travis/build/bitcoin/bitcoin/ci/scratch/build/bitcoin-x86_64-apple-darwin16/test/functional/test_framework/util.py", line 49, in assert_equal
      raise AssertionError("not(%s)" % " == ".join(str(arg) for arg in (thing1, thing2) + args))

  AssertionError: not(0E-8 == 0.09170997)
  2020-07-19T05:44:17.293000Z TestFramework (INFO): Stopping nodes
  ```

  At Marco's suggestion, cherry-picked part of #19134 to nicely simplify using `wait_until`.

ACKs for top commit:
  vasild:
    ACK 12410b1fe

Tree-SHA512: 615f509883682fd693e578b259cba35a9fa0bc519f1394e88c857e8b0650bfec5397bfa856cfa9e6d5ef81d0ee6ad02e4ad2b0eb0bd530b4c281cbe3e663790b

0 files changed, 0 insertions, 0 deletions