title: Auto upgrade button missing
body: <p>I've got a jenkins CI installed from a debian package (1.424.6 version, Debian/Ubuntu distribution, running on ubuntu 12.04). I read on the web that jenkins provides an automatic upgrade button, just like in <img src="https://i.stack.imgur.com/Zq8ga.png" alt="this link">. But I don't have such thing on my jenkins. I tried to find answers on google and in jenkins config, but failed. Maybe it's impossible for debian/ubuntu installed package?</p>