bpo-34523: Fix config_init_fs_encoding() (GH-8991)

Call config_init_fs_encoding() if filesystem_errors is not NULL but filesystem_encoding is NULL.

Author: vstinner

Python/coreconfig.c

@@ -1344,7 +1344,7 @@ _PyCoreConfig_Read(_PyCoreConfig *config)
  config->argc = 0;
  }
 
- if (config->filesystem_encoding == NULL && config->filesystem_errors == NULL) {
+ if (config->filesystem_encoding == NULL || config->filesystem_errors == NULL) {
  err = config_init_fs_encoding(config);
  if (_Py_INIT_FAILED(err)) {
  return err;