GSConfig should not affect log level setting

[thvasilo]

GSConfig is a wrapper object for GraphStorm but it includes code that enforces log level at the application level:

graphstorm/python/graphstorm/config/argument.py

Lines 190 to 198 in f0c38bb

	log_level = get_log_level(cmd_args.logging_level) \
	if hasattr(cmd_args, "logging_level") else logging.INFO
	log_file = cmd_args.logging_file if hasattr(cmd_args, "logging_file") else None
	if log_file is None:
	# need to force the logging to reset the existing logging handlers
	# in order to make sure this config is effective.
	logging.basicConfig(level=log_level, force=True)
	else:
	logging.basicConfig(filename=log_file, level=log_level, force=True)

The caller program should get to establish the logging level, using logging.basicConfig(level=log_level, force=True) overrides user intent, especially when the GraphStorm API is used.