Remove superfluous transaction.

lib/pleroma/web/twitter_api/twitter_api.ex

@@ -316,7 +316,6 @@ defmodule Pleroma.Web.TwitterAPI.TwitterAPI do
   end
 
   def context_to_conversation_id(context) do
-    {:ok, id} = Repo.transaction(fn ->
     with %Object{id: id} <- Object.get_cached_by_ap_id(context) do
       id
     else _e ->
@@ -324,8 +323,6 @@ defmodule Pleroma.Web.TwitterAPI.TwitterAPI do
       {:ok, %{id: id}} = Repo.insert(changeset)
       id
     end
-    end)
-    id
   end
 
   def conversation_id_to_context(id) do