util.startup: Fix async waiting for last shutdown steps

Observed problem: When shutting down prosody would immediately exit
after waiting for s2s connections to close, skipping the last cleanup
events and reporting the exit reason and code.

This happens because prosody.main_thread is in a waiting state and
queuing startup.shutdown is dispatched trough the main loop via
nexttick, but since the main loop was no longer running at that point it
proceeded to the end of the prosody script and exited there.

0 files changed, 0 insertions, 0 deletions