This should help you:
https://organicdesign.nz/Simple_video_streaming_with_ffserver
https://www.youtube.com/watch?v=cObC-nNUIwI
You should be able to tailor this info to your needs.
Like:
ffmpeg -r 25 -s 1600x900 -f x11grab -i :0.0 http://localhost:8090/feed1.ffm
and have a separate feed for audio if you want.
And:
ffmpeg -f alsa -i hw:0,0 -acodec pcm_s16le http://localhost:8090/feed2.ffm
Or: Figure out how to get the two to play nice together in a one liner.
Try useing these ACL settings:
ACL allow 127.0.0.1
ACL allow 192.168.0.0 192.168.255.255
With this Command:
ffserver >/dev/null 2>&1 &
ffmpeg -video_size 1600x900 -framerate 20 -f x11grab -i :0.0 \
-f alsa -ac 2 -i hw:0 http://127.0.0.1:8090/feed1.ffm
It seems as though the connection may be being refused because of the word localhost.