Handle HTTP requests one-by-one

[github-actions]

This is an automatic cherry-pick of 1b71543bc99587dccabad770929fe6c47c3913f2

The original PR was #238 with message:

By handling HTTP requests one-by-one rather than spawning a thread for each request, an attacker can no longer force the app to create multiple threads. It also leads to simpler code and fixes the failure to free the memory allocated for the request.

Checklist before requesting a review

• I have performed a self-review of my own code
• I have verified that the code builds perfectly fine on my local system
• I have added tests that prove my fix is effective or that my feature works
• I have commented my code, particularly in hard-to-understand areas
• I have verified that my code follows the style already available in the repository
• I have made corresponding changes to the documentation