fix host fs mount failing on first start with installer

Author: nzbr

modules/installer.nix

@@ -54,7 +54,10 @@ with builtins; with lib; {
 
         contents = [
           { source = config.environment.etc."wsl.conf".source; target = "/etc/wsl.conf"; }
+          { source = config.environment.etc."fstab".source; target = "/etc/fstab"; }
           { source = passwd; target = "/etc/passwd"; }
+          { source = "${pkgs.busybox}/bin/busybox"; target = "/bin/sh"; }
+          { source = "${pkgs.busybox}/bin/busybox"; target = "/bin/mount"; }
         ];
       };