[#1072] Revert reactor restart code.

Problem description
===================

Test suite hangs on Python 2.5 when it uses this way of restarting the reactor.


Why we got into this (5 whys)
=============================

The package was updated... but since there are no tests in the package it only failed when I tried to use with the server.


Changes description
===================

Reverted reactor restart to the old way.


How to try and test the changes
===============================

reviewers @alibotean 

There is nothing much here to test.
There will be another review for the server using this new package.