deployment module: set configuration explicitly (#315)

this change is a no-op (it merely indents the option definitions by one,
by setting `config` explicitly) and prepares an addition of option
declarations that would otherwise be lost in the huge diff.

Reviewed-on: Fediversity/Fediversity#315
Reviewed-by: kiara Grouwstra <kiara@procolix.eu>

deployment/default.nix

@@ -44,6 +44,7 @@ in
 { providers, ... }:
 
 {
+  config = {
     providers = { inherit (nixops4.modules.nixops4Provider) local; };
 
     resources =
@@ -178,4 +179,5 @@ in
           }
         );
       };
+  };
 }