I see these 2 messages in the log:
2018/05/04 13:59:18 [warn] 7059#7059: audio_encoder_process_init: failed to get AAC encoder, audio encoding is disabled. recompile libavcodec with libfdk_aac to enable it
2018/05/04 13:59:39 [info] 7057#7057: *1 client timed out (110: Connection timed out) while waiting for request, client: 172.31.30.68, server: 0.0.0.0:88
The 2nd one reaping many times