Add virtual storage name for praefect
part of gitaly#2066
In gitaly!1525 (merged) we are adding a virtual storage name field for praefect. This MR adds that in gdk's praefect config
Edited by John Cai
part of gitaly#2066
In gitaly!1525 (merged) we are adding a virtual storage name field for praefect. This MR adds that in gdk's praefect config