message: test: Default --previous-releases to false if dir is empty
diff: @@ -156,7 +156,7 @@ class BitcoinTestFramework(metaclass=BitcoinTestMetaClass):
  parser.add_argument("--portseed", dest="port_seed", default=os.getpid(), type=int,
  help="The seed to use for assigning port numbers (default: current process id)")
  parser.add_argument("--previous-releases", dest="prev_releases", action="store_true",
  - default=os.path.isdir(previous_releases_path),
  + default=os.path.isdir(previous_releases_path) and bool(os.listdir(previous_releases_path)),
  help="Force test of previous releases (default: %(default)s)")
  parser.add_argument("--coveragedir", dest="coveragedir",
  help="Write tested RPC commands into this directory")
  