Comment 6 for bug 193558

Until the solution comes:
(A) execute in Terminal: sudo apt-get -o Acquire::http::Dl-Limit=80 upgrade
It will limit the download to 80kb/s
or

(B) 1. Execute in Terminal:

gksu gedit /etc/apt/apt.conf.d/custom-limit-bandwidth

 2. Add these lines:

Acquire
{
  http
  {
    Dl-Limit "80"; // 80Kb/sec maximum download rate
  };
};

 3. Edit "80" to your preference.
 4. Save and close gedit (text editor)

 5. Execute in Terminal:

sudo apt-get update
sudo apt-get upgrade

 5. Enjoy!