o Minor bugfixes (logging, relay):
    - Remove a log_warn() that has been forgotten when an introduction point
      successfully established a hidden service prop224 circuit with a client.
    - Three other log_warn() for an introduction point have been changed to
      protocol warning because they can be failure from the network and are
      not relevant to the operator. Fixes bug 23078; bugfix on
      tor-0.3.0.1-alpha and tor-0.3.0.2-alpha.