When connection to FTL ingest is lost, ftl_event() calls
obs_output_signal_stop() to trigger a reconnect. However, during the
reconnect delay, send_thread is still waiting on send_sem semaphore.
After the delay, ftl_stream_start() is called, which in turn resets
the semaphore and creates a new send_thread. Old send_thread now exits
the loop and triggers another reconnect and the whole process repeats
again. The fix resets the semaphore in ftl_event() so the old
send_thread exits immediately.
7029304b32