Fix exception when running the nginx agent plugin with Python 3.8
requested to merge 1-exception-exception-localhost-8060-a-bytes-like-object-is-required-not-str into main
It uses the fixed version from https://github.com/tribe29/checkmk/blob/d04639032a0c416cd8be986bc26b6571a4e5fe86/agents/plugins/nginx_status.py
Closes #1 (closed)