Update appsettings.json

fix closed brace

src/VirtoCommerce.Platform.Web/appsettings.json

@@ -106,6 +106,7 @@
         // Allows assigning a domain name to a store. An alternative way is using
         // "localhost": "B2B-store"
       }
+    }
   },
   "Auth": {
     //auth server's url, e.g. https://localhost:5051/ or https://auth.example.com/ or leave empty for mode when authorization