update old app url

Author: lihebi

src/pages/login.tsx

@@ -55,13 +55,13 @@ export default function Login(): JSX.Element {
         >
           Looking for the previous version of CodePod? You can find it at{" "}
           <a
-            href="https://app.codepod.io"
+            href="https://old-app.codepod.io"
             target="_blank"
             style={{
               color: "black",
             }}
           >
-            app.codepod.io (deprecated)
+            old-app.codepod.io (deprecated)
           </a>
           . Note that this version is deprecated and the{" "}
           <span