refactor(ruff): multiple changes to clear ruff issues Fix a couple of missing returns of booleans for security checks. Turns an implicit return None into an explicit return False. Fix loop index variable being reassigned inside loop by renaming index variable. 2 instances. Consolidate 2 isinstance calls to 1 with tuple class argument. Replace dict(list comprehension) with dict conprehension. Variable renames. Removal of unused variable. Whitespace fixes. sort imports

#! /bin/sh

# if there are multiple trackers, d=demo t=tracker ...
# returns last one for testing that server is up. Does not test
# each tracker.
tracker=$(ps -ef | sed -ne '/roundup-server/s/^.*\s\(\w*\)=.*$/\1/p')
wget -q -O /dev/null --proxy off --no-verbose http://localhost:8080/"${tracker:-demo}"/