Although it should never happen that a file descriptor is suddenly
closed, it appeared that this happens on linux 64bit when using
FMODex... Not really sure how useful this is, but at least now the
viewer just continues to work, as if -say- the socket was closed
remotely. Before the curl thread would go into a tight loop that it
wouldn't recover from until the watchdog thread terminated the viewer.
6dcda3595e