fix: config always get override by defaults

[frostming]

Signed-off-by: Frost Ming me@frostming.com

Because confRemoter calls updateConf, which in turn calls handleCustomConf and which calls mergeDeep(Defaults, userConf)

The values from the default will always take precedence to override the existing values, this is unexpected.

updateConf
  ↑ mergeDeep(this.conf, handleCustomConf(nConf)）
                                ↑ mergeDeep(Defaults, nConf)

This patch fixes #718

[frostming]

Oh, I didn't notice #719, feel free to choose either one.

[qwqcode]

Thank you for your time to careful review and PR. Based on the solution offered in the PR, I have refactored the related API configurations (opened a new PR #722 and included unit tests), which should address this issue. The unit tests are in place to ensure that this problem won't occur again in the future. 😃