nixos/outline: fix s3 storage (#302567)

ReadWritePaths were crashing the unit due to non-existent folders on s3 configuration

https://github.com/NixOS/nixpkgs/pull/298892#issuecomment-2042666854

nixos/modules/services/web-apps/outline.nix

@@ -784,7 +784,7 @@ in
         # onboarding files:
         WorkingDirectory = "${cfg.package}/share/outline";
         # In case this directory is not in /var/lib/outline, it needs to be made writable explicitly
-        ReadWritePaths = [ cfg.storage.localRootDir ];
+        ReadWritePaths = lib.mkIf (cfg.storage.storageType == "local") [ cfg.storage.localRootDir ];
       };
     };
   };