Keep ffmpeg running when using SRT as output and in listener mode

[longkas]

Summary of the bug:
Using SRT as the output and set SRT to listener mode, when the caller quits the ffmpeg quits also, it would be great if keep ffmpeg running and listening for new caller connections

How to reproduce:

% LISTENER: 
   ffmpeg -re -i file.mp4 -c copy -f mpegts "srt://:8686?mode=listener&transtype=live"

  CALLER:
   ffmpeg -i "srt://:8686?mode=caller&transtype=live" -c copy -f mpegts file.ts


#ffmpeg -version
ffmpeg version N-97994-g83fa39e Copyright (c) 2000-2020 the FFmpeg developers
built with gcc 9 (GCC)
configuration: --prefix=/root/ffmpeg_build --pkg-config-flags=--static --extra-cflags=-I/root/ffmpeg_build/include --extra-ldflags=-L/root/ffmpeg_build/lib --extra-libs=-lpthread --extra-libs=-lm --bindir=/root/bin --enable-gpl --enable-libfdk_aac --enable-libfreetype --enable-libmp3lame --enable-libopus --enable-libvpx --enable-libx264 --enable-libx265 --enable-libsrt --enable-nonfree
libavutil      56. 49.100 / 56. 49.100
libavcodec     58. 89.100 / 58. 89.100
libavformat    58. 43.100 / 58. 43.100
libavdevice    58.  9.103 / 58.  9.103
libavfilter     7. 83.100 /  7. 83.100
libswscale      5.  6.101 /  5.  6.101
libswresample   3.  6.100 /  3.  6.100
libpostproc    55.  6.100 / 55.  6.100

[dubrsl]

You can use fifo for solve it.
Example:

ffmpeg   "... input and encode options ..." -f tee "[f=mpegts:use_fifo=1:fifo_options='drop_pkts_on_overflow=1:attempt_recovery=1:recover_any_error=1:restart_with_keyframe=1\']srt://:4200?mode=listener&transtype=live|Other tee output"