Merge branch 'mf/curl-select-fdset' into maint

* mf/curl-select-fdset:
  http: drop "local" member from request struct
  http.c: Rely on select instead of tracking whether data was received
  http.c: Use timeout suggested by curl instead of fixed 50ms timeout
  http.c: Use curl_multi_fdset to select on curl fds instead of just sleeping