Fix virtualbox deployment for 19.09

Without this, starting the virtualbox guest service fails during machine activation.
This is due to an incompatible NixOS machine base image.
Fix this by using an updated version of nixops.

pkgs/nixops/release.nix.patch

@@ -0,0 +1,34 @@
+--- a/release.nix
++++ b/release.nix
+@@ -1,6 +1,7 @@
+ { nixopsSrc ? { outPath = ./.; revCount = 0; shortRev = "abcdef"; rev = "HEAD"; }
+ , officialRelease ? false
+ , nixpkgs ? <nixpkgs>
++, pluginData
+ , p ? (p: [ ])
+ }:
+
+@@ -10,11 +11,10 @@ let
+
+   allPlugins = let
+     plugins = let
+-      allPluginVers = import ./data.nix;
++      allPluginVers = pluginData;
+       fetch = v:
+         pkgs.fetchFromGitHub {
+-          inherit (v) owner repo sha256;
+-          rev = "v${v.version}";
++          inherit (v) owner repo sha256 rev;
+         };
+       srcDrv = v: (fetch v) + "/release.nix";
+     in self: let
+@@ -83,4 +83,4 @@
+# Remove annoying debug message that's shown in nix-shell while evaluating this file
+           pysqlite
+           typing
+           pluggy
+-        ] ++ pkgs.lib.traceValFn (x: "Using plugins: " + builtins.toJSON x) (map (d: d.build.${system}) (p allPlugins));
++        ] ++ (map (d: d.build.${system}) (p allPlugins));
+
+
+       # For "nix-build --run-env".