Build process outputs each line twice

Don't propagate logs going to stdout to avoid duplicate messages

Co-Authored-By: Jeffrey Zhang <jeffrey.zhang@99cloud.net>
Change-Id: I52da42adc40aa5d468d1c0c1134e65689916a2a8
Closes-Bug: #1620239

kolla/image/build.py

@@ -63,6 +63,7 @@ def make_a_logger(conf=None, image_name=None):
     if not log.handlers:
         if conf is None or not conf.logs_dir or not image_name:
             handler = logging.StreamHandler(sys.stdout)
+            log.propagate = False
         else:
             filename = os.path.join(conf.logs_dir, "%s.log" % image_name)
             handler = logging.FileHandler(filename, delay=True)