Remove stopgap code for broken version upgrade from 3.17
Created by: eseliger
While looking around, I've found this line with a TODO comment next to it that it can be removed after Oct 1, 2020. As far as I understand it, it was used as a stopgap to fix the 3.17 version of Sourcegraph not properly updating to a newer version, because we forgot to bake in the correct version string (was v0.0.0+dev
, instead of v3.17.0
).