manatee: Open port 443 for nginx

hosts/manatee/modules/nginx/default.nix

@@ -18,5 +18,11 @@ in
         recommendedTlsSettings = true;
       };
     };
+
+    networking = {
+      firewall = {
+        allowedTCPPorts = [ 443 ];
+      };
+    };
   };
 }