Fix password reset for non-test env

Fixes `Plug.Conn.NotSentError` that causes a 5xx error in response
instead of 404 and 400.

Fixes pattern matching error caused by different response format
in test and non-test env: `Pleroma.Emails.Mailer.deliver_async` returns
:ok when PleromaJobQueue is enabled and `{:ok, _}` when it's disabled.
In tests, it's disabled.

test/web/twitter_api/twitter_api_controller_test.exs

@@ -1119,14 +1119,14 @@ defmodule Pleroma.Web.TwitterAPI.ControllerTest do
     test "it returns 404 when user is not found", %{conn: conn, user: user} do
       conn = post(conn, "/api/account/password_reset?email=nonexisting_#{user.email}")
       assert conn.status == 404
-      refute conn.resp_body
+      assert conn.resp_body == ""
     end
 
     test "it returns 400 when user is not local", %{conn: conn, user: user} do
       {:ok, user} = Repo.update(Changeset.change(user, local: false))
       conn = post(conn, "/api/account/password_reset?email=#{user.email}")
       assert conn.status == 400
-      refute conn.resp_body
+      assert conn.resp_body == ""
     end
   end