Session analyzer is not working

[JohnBonJo]

I'm running it with docker

In docker/redis/Dockerfile I have changed redis:alpine to redis:6.2.7-alpine because I needed a lower redis rdb version to use it with a tool called redis-rdb-tools.

But it is not working. Also the web server displays empty data.
I've tried to trace the problem and I believe it is in session analyzer.
https://github.com/mushorg/tanner/blob/main/tanner/sessions/session_analyzer.py#L21

Changes from mushorg/tanner:main

Any help is appreciated
@toyray @afeena @mzfr