Missing field in update subtraction request
GET subtraction request returns the subtraction details, including the `linked_samples` array:
```
data: {
  count: 7,
  file: {id: "17qp283m-ATgenomeTAIR9.171", name: "ATgenomeTAIR9.171"},
  gc :{a: 0.319, t: 0.319, g: 0.18, c: 0.18, n: 0.002},
  id: "000",
  is_host: true,
  job: {id: "8n83tngx"},
  linked_samples: [{…}, {…}],
  nickname: "edited7",
  ready: true,
  user: {id: "naomis"}
}
```

UPDATE subtraction request returns the subtraction details without the array:
```
data: {
  count: 7,
  file: {id:  "17qp283m-ATgenomeTAIR9.171", name:  "ATgenomeTAIR9.171"},
  gc: {a: 0.319, t: 0.319, g: 0.18, c: 0.18, n: 0.002},
  id: "000",
  is_host: true,
  job: {id: "8n83tngx"},
  nickname: "CHANGED",
  ready: true,
  user: {id: "naomis"}
}
```
diff --git a/virtool/api/subtractions.py b/virtool/api/subtractions.py
index ec7a6dfdc..80c6543e9 100644
--- a/virtool/api/subtractions.py
+++ b/virtool/api/subtractions.py
@@ -156,6 +156,8 @@ async def edit(req):
     if document is None:
         return not_found()
 
+    document["linked_samples"] = await virtool.db.subtractions.get_linked_samples(db, subtraction_id)
+
     return json_response(virtool.utils.base_processor(document))
 
 
['virtool/api/subtractions.py']