Typo in documentation of http original_src filter (#36060)

The doc is about http original_src filter while in the example, the
listed type is that of listener filter.

![image](https://github.com/user-attachments/assets/a6e6e473-9d02-4e92-a9e7-3f3bca7291ab)

Existing example will result in following error:
Didn't find a registered implementation for
'envoy.filters.http.original_src' with type URL:
'envoy.extensions.filters.listener.original_src.v3.OriginalSrc'

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Commit Message: Typo in documentation of http original_src filter
Additional Description:
Risk Level: Low
Testing: Locally
Docs Changes: Yes
Release Notes: Typo in documentation of http original_src filter
Platform Specific Features:
[Optional Runtime guard:]
[Optional Fixes #Issue]
[Optional Fixes commit #PR or SHA]
[Optional Deprecated:]
[Optional [API
Considerations](https://github.com/envoyproxy/envoy/blob/main/api/review_checklist.md):]

Signed-off-by: Ravi Gupta <[email protected]>

docs/root/configuration/http/http_filters/original_src_filter.rst

@@ -70,7 +70,7 @@ The following example configures Envoy to use the original source for all connec
   http_filters:
     - name: envoy.filters.http.original_src
       typed_config:
-        "@type": type.googleapis.com/envoy.extensions.filters.listener.original_src.v3.OriginalSrc
+        "@type": type.googleapis.com/envoy.extensions.filters.http.original_src.v3.OriginalSrc
         mark: 123
     - name: envoy.filters.http.router
       typed_config: