log: Guard against setting g_log_set_writer_func() multiple times
Some tests recently started failing:
GLib-ERROR **: 08:25:34.271: g_log_set_writer_func() called multiple times
So guard against it.
Addresses parts of #841 (closed)
This is only treating the symptoms as I've not checked in detail why now it ends up being called twice.
Edited by Evangelos Ribeiro Tzaras