cleanup: drop last traces of kallithea-config The kallithea-config sources were removed in commit 213085032127e941a3bd93d0e510828a9d87bf32 but an entry point was still created by setup.py. Moreover, the ini file still referenced this, instead of kallithea-cli (config-create).

# requirements.txt file for use as "pip install -r requirements.txt" as a
# readthedocs compatible alternative to "pip install -e ." which is a working
# alternative to "setup.py develop" which doesn't work with Mercurial 3.7
.