fix: post summaries are being repeated in the list (#105)

* fix: post summaries are being repeated in the list

src/discussions/posts/data/thunks.js

@@ -93,7 +93,7 @@ export function fetchThreads(courseId, {
   author = null,
   filters = {},
   page = 1,
-} = {}, posts = []) {
+} = {}) {
   const options = {
     orderBy,
     topicIds,
@@ -122,7 +122,6 @@ export function fetchThreads(courseId, {
     try {
       dispatch(fetchThreadsRequest({ courseId }));
       const data = await getThreads(courseId, options);
-      data.results = [...posts, ...data.results];
       const normalisedData = normaliseThreads(camelCaseObject(data));
       dispatch(fetchThreadsSuccess({ ...normalisedData, page, author }));
     } catch (error) {