Fix Transmogrifier tests

These tests relied on the removed Fetcher.fetch_object_from_id!/2 function injecting the error tuple into a log message with the exact words "Object containment failed."

We will keep this behavior by generating a similar log message, but perhaps this should do a better job of matching on the error tuple returned by Transmogrifier.handle_incoming/1

lib/pleroma/object/fetcher.ex

@@ -157,6 +157,10 @@ defmodule Pleroma.Object.Fetcher do
       {:scheme, false} ->
         {:error, "URI Scheme Invalid"}
 
+      {:containment, e} ->
+        Logger.info("Error while fetching #{id}: Object containment failed. #{inspect(e)}")
+        {:error, e}
+
       {:transmogrifier, {:error, {:reject, e}}} ->
         Logger.info("Rejected #{id} while fetching: #{inspect(e)}")
         {:reject, e}