docs(convex): fix import statement for authConfig (#6861)

docs/content/docs/integrations/convex.mdx

@@ -147,7 +147,7 @@ If you're not using Next.js, support for other frameworks is documented in the [
         import { DataModel } from "./_generated/dataModel";
         import { query } from "./_generated/server";
         import { betterAuth } from "better-auth";
-        import { authConfig } from "./auth.config";
+        import authConfig from "./auth.config";
 
         const siteUrl = process.env.SITE_URL!;
 
@@ -392,4 +392,4 @@ export async function updatePassword({
         newPassword,
     });
 }
-```
+```