message: Fix propagation for Jaeger native example.
diff: @@ -10,11 +10,16 @@ app = Flask(__name__)
  TRACE_HEADERS_TO_PROPAGATE = [
  'X-Ot-Span-Context',
  'X-Request-Id',
  +
  + # Zipkin headers
  'X-B3-TraceId',
  'X-B3-SpanId',
  'X-B3-ParentSpanId',
  'X-B3-Sampled',
  - 'X-B3-Flags'
  + 'X-B3-Flags',
  +
  + # Jaeger header (for native client)
  + "uber-trace-id"
  ]
  @app.route('/service/<service_number>')
  