fix(backend): Fix return url post top-up (#9392)

### Changes 🏗️

Fix return URL post-top-up, when FRONT_END_BASE_URL is used.

### Checklist 📋

#### For code changes:
- [ ] I have clearly listed my changes in the PR description
- [ ] I have made a test plan
- [ ] I have tested my changes according to the test plan:
  <!-- Put your test plan here: -->
  - [ ] ...

<details>
  <summary>Example test plan</summary>
  
  - [ ] Create from scratch and execute an agent with at least 3 blocks
- [ ] Import an agent from file upload, and confirm it executes
correctly
  - [ ] Upload agent to marketplace
- [ ] Import an agent from marketplace and confirm it executes correctly
  - [ ] Edit an agent from monitor, and confirm it executes correctly
</details>

#### For configuration changes:
- [ ] `.env.example` is updated or already compatible with my changes
- [ ] `docker-compose.yml` is updated or already compatible with my
changes
- [ ] I have included a list of my configuration changes in the PR
description (under **Changes**)

<details>
  <summary>Examples of configuration changes</summary>

  - Changing ports
  - Adding new services that need to communicate with each other
  - Secrets or environment variable changes
  - New or infrastructure changes such as databases
</details>

autogpt_platform/backend/backend/data/credit.py

@@ -421,9 +421,9 @@ class UserCredit(UserCreditBase):
             ui_mode="hosted",
             payment_intent_data={"setup_future_usage": "off_session"},
             saved_payment_method_options={"payment_method_save": "enabled"},
-            success_url=settings.config.platform_base_url
+            success_url=settings.config.frontend_base_url
             + "/marketplace/credits?topup=success",
-            cancel_url=settings.config.platform_base_url
+            cancel_url=settings.config.frontend_base_url
             + "/marketplace/credits?topup=cancel",
         )
 

autogpt_platform/frontend/src/app/marketplace/(user)/credits/page.tsx

@@ -203,6 +203,9 @@ export default function CreditsPage() {
             executions are happening.
           </p>
           <br />
+          {transactionHistory.transactions.length === 0 && (
+            <p className="text-neutral-600">No transactions found.</p>
+          )}
           <Table
             className={
               transactionHistory.transactions.length === 0 ? "hidden" : ""