Comment # 2 on bug 57214 from Patrick Ohly

One solution proposed on the Neon list is to close the file descriptor used by
Neon in a second thread. That should make neon return while blocking on IO via
that descriptor.

In SyncEvolution, the main thread would have to be the one which does the
closing because that needs to integrate with the main event loop. A second
thread would be the one which calls neon.