mosquitto_pub -l hangs when stdin ends.

[majekw]

Hello,

since 7d954fa mosquitto_pub -l fails frequently to exit after stdin ends. There must be some race condition as when I test it with strace -f it hangs every time.

It looks like old behavior was:

1. stdin ends -> set status to STATUS_WAITING
2. in next loop call mosquitto_disconnect_v5, sleep,
3. wait for my_disconnect_callback to set connected to false
4. exit loop
5. stop mosquitto_loop

After 'fix' it changed to:

1. stdin ends -> set status to STATUS_WAITING and stdin_finished to true
2. loop ends without mosquitto_disconnect_v5 and sleep
3. mosquitto_loop_stop is called, but it probably hangs here