Advise need for an interim upgrade version if < 4.2.9
Created by: eileenmcnaughton
https://github.com/civicrm/civicrm-core/pull/11864
Note that the actual earliest version that will work on 4.7 & the best interim version could be a bit debated but I think the most important thing is to give an instruction that will work for the (few if any) people dealing with really old versions