log: Don't disable loggers when loading fileConfig

The default when loading config for logging from a file is to disable
existing loggers. Since some loggers are created before logging is set
up, these loggers were disabled if logging/config_file is set.

(cherry picked from commit cb0387c46d7c65d141355ce716764f7b05ef3f3f)

Conflicts:
	docs/changelog.rst
docs: Use :confval:-syntax, add fixes for logging issue

(cherry picked from commit 524043f6b7ee4c3120d6e7e00bad154e4ad82668)

Conflicts:
	docs/changelog.rst