Follow-up on PR #5334: Allow to create httpClient from app
This issue is to follow up on the changes proposed in PR #5334 (https://github.com/eggjs/egg/pull/5334). The PR aims to allow the creation of httpClient from the app. 

Comment: https://github.com/eggjs/egg/pull/5334#issuecomment-1234567890

Assignee: @fengmk2