o Minor bugfixes (hidden service client):
    - Seven very fast consecutive requests to the same .onion address
      triggers 7 descriptor fetches. The first six each pick a directory
      (there are 6 overall) and the seventh one wasn't able to pick one
      which was triggering a close on all current directory connections. It
      has been fixed by not closing them if we have pending directory fetch.
      Fixes bug 15937; bugfix on tor-0.2.7.1-alpha.