Surely in this tutorial are in need is a Mozilla Firefox browser in this tutorial Writer Using Mozilla 3.5.3 (I'll know if there are changes to the version and update my tricks in the pages of this article)
For the first step Type about: config then search through the filter column the words below:
A
network.http.pipelining
network.http.pipelining.maxrequests
network.http.proxy.pipelining
Then Change the Value of Being IN