message: docs: fix minor style issue in tracing.rst
  Remove an unnecessary bullet list to make the link to the v2 API
  reference inlined.
diff: @@ -107,7 +107,5 @@ Envoy automatically sends spans to tracing collectors. Depending on the tracing
  multiple spans are stitched together using common information such as the globally unique
  request ID :ref:`config_http_conn_man_headers_x-request-id` (LightStep) or
  the trace ID configuration (Zipkin and Datadog). See
  -
  -* :ref:`v2 API reference <envoy_api_msg_config.trace.v2.Tracing>`
  -
  +:ref:`v2 API reference <envoy_api_msg_config.trace.v2.Tracing>`
  for more information on how to setup tracing in Envoy.
  