Mailcow: Update.

Change-Id: I47c7c6e462fa69513ba6b7c33bfa23665426b257
diff --git a/mailcow/default.nix b/mailcow/default.nix
index 05a0b1d..0408755 100644
--- a/mailcow/default.nix
+++ b/mailcow/default.nix
@@ -1,6 +1,15 @@
 { system ? builtins.currentSystem }:
 let
-  pkgs = import <nixpkgs> { inherit system; };
+  pkgs = import <nixpkgs> {
+    inherit system;
+    overlays = [
+      (self: super: {
+        docker = super.docker.override {
+          iptables = self.iptables-legacy;
+        };
+      })
+    ];
+  };
 
 in
 let
@@ -67,6 +76,7 @@
       ${pkgs.docker-compose}/bin/docker-compose -f /mailcow-dockerized/docker-compose.yml -f ${dockerComposeOverrideYaml}/docker-compose.override.yml build
 
       ${pkgs.busybox}/bin/mkdir -p /tmp /run/{mysql,mysql-socket}
+      ${pkgs.busybox}/bin/chmod u+w /mailcow-dockerized/data/web/templates/cache
       exec ${pkgs.docker-compose}/bin/docker-compose --env-file /mailcow-dockerized/mailcow.conf -f /mailcow-dockerized/docker-compose.yml -f ${dockerComposeOverrideYaml}/docker-compose.override.yml up --remove-orphans
     '';