Handle Leak due to missing InternetCloseHandle

[parzel]

Describe the bug
I identified a [handle leak]((mjwhitta/win#3) in mjwhitta's WinINet/WinHTTP library, which leads to a state where the library cannot connect anymore due to being out of handles. As the unpatched code is used in sliver, this should also be an issue when using wininet as driver and lead to dying implants.

To Reproduce
There is a minimal example to observe the handle leak in this issue. Theoretically when running an implant long enough without the go HTTP library, behavior should be the same and the implant should die.

Expected behavior
The opened handles must be closed properly. There has been a fix in the library.

Desktop (please complete the following information):

• OS: Windows
• Version: N/A