Submitted by: @hvlad

If client application
- uses local (stack based) status vector when call ISC API functions, and
- uses events, and
- connection with server is broken,
then random AV could happens in some of application thread's.

The reason is that fbclient saves pointer to the user status-vector at entry to the
all ISC API functions and later report network error happens at event listener thread
using that saved pointer to the status-vector. If stack variable is out of scope it
means events listener thread wrote to the some "random" place at the stack of
another thread.

Commits: 817919c