[sociald] Ensure that network timeouts are dealt with by finished() handlers. Contributes to JB#18789
[sociald] Ensure that network timeouts are dealt with by finished() handlers. Contributes to JB#18789

This commit ensures that if a network timeout error occurs, the
finished handler connected to the network reply object handles
the error, rather than decrementing the semaphore directly within
the timeout handler.

This allows specific sync adapters to handle timeout errors and
set the appropriate failure flags / state data appropriately.

Contributes to JB#18789

rainisto/buteo-sync-plugins-social,rainisto/buteo-sync-plugins-social