Fix out-of-bounds crash in origin selection popup (#6202)

### What
* Closes #6142

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* Using examples from latest `main` build:
[rerun.io/viewer](https://rerun.io/viewer/pr/6202?manifest_url=https://app.rerun.io/version/main/examples_manifest.json)
* Using full set of examples from `nightly` build:
[rerun.io/viewer](https://rerun.io/viewer/pr/6202?manifest_url=https://app.rerun.io/version/nightly/examples_manifest.json)
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checklist](https://github.com/rerun-io/rerun/blob/main/tests/python/release_checklist)!

- [PR Build Summary](https://build.rerun.io/pr/6202)
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crates/re_viewer/src/ui/space_view_space_origin_ui.rs

@@ -144,9 +144,11 @@ fn space_view_space_origin_widget_editing_ui(
 
     if let Some(selected_suggestion) = state.selected_suggestion {
         if enter_key_hit {
-            let origin = &filtered_space_view_suggestions[selected_suggestion].space_origin;
-            state.origin_string = origin.to_string();
-            control_flow = ControlFlow::Break(Some(origin.clone()));
+            if let Some(suggestion) = filtered_space_view_suggestions.get(selected_suggestion) {
+                let origin = &suggestion.space_origin;
+                state.origin_string = origin.to_string();
+                control_flow = ControlFlow::Break(Some(origin.clone()));
+            }
         }
     }