Better publisher reconnection with reclaim session

[vincentfretin]

We discussed publisher reconnection in #73 where I ended up tuning the session_timeout parameter, but this still has a long delay of 38s before the publisher can talk again.
I saw this comment on the mailing-list about session reclaim:
https://groups.google.com/g/meetecho-janus/c/tPNYtfMek6s/m/hbvCGjjLAAAJ
Maybe worth investigating, this would need changes in the reconnection logic in naf-janus-adapter as well.

[vincentfretin]

Reclaiming a session was implemented in april 2018, see relevant commits:
meetecho/janus-gateway@74f537b...a53ea18

You need an value >0 for reclaim-session-timeout for sure, changes in naf-janus-adapter, maybe a change in minijanus. I'm not sure if there is a change in janus-plugin-sfu or janus-plugin-rs needed. I didn't investigate further than this.