fix(log): default log level (#491)

ddns/__main__.py

@@ -126,7 +126,7 @@ def main():
         sys.stderr = TextIOWrapper(sys.stderr.buffer, encoding='utf-8')
     init_config(__description__, __doc__, __version__, build_date)
 
-    log_level = get_config('log.level')
+    log_level = get_config('log.level', INFO)
     log_format = get_config('log.format')
     if log_format:
         # A custom log format is already set; no further action is required.