MM-18623 - invalid reply-count displayed (#12364)

* fixed thread creator, fixed default behaviour of fetching posts
* handle reply-count in getPostThread code path

api4/post.go

@@ -384,8 +384,11 @@ func getPostThread(c *Context, w http.ResponseWriter, r *http.Request) {
 	if c.Err != nil {
 		return
 	}
-
-	list, err := c.App.GetPostThread(c.Params.PostId)
+	skipFetchThreads := false
+	if r.URL.Query().Get("fetchThreads") == "false" {
+		skipFetchThreads = true
+	}
+	list, err := c.App.GetPostThread(c.Params.PostId, skipFetchThreads)
 	if err != nil {
 		c.Err = err
 		return