main: Actually set logger level based on user's configuration.

import2ledger/__main__.py

@@ -71,6 +71,7 @@ def setup_logger(logger, main_config, stream):
     handler = logging.StreamHandler(stream)
     handler.setFormatter(formatter)
     logger.addHandler(handler)
+    logger.setLevel(main_config.get_loglevel())
 
 def decimal_context(base=decimal.BasicContext):
     context = base.copy()