Add CA root certificate path for Haiku

What does this PR do?

Add the root certificate path for Haiku so that http.download() from sites like github.com work properly.

How does this PR change Premake's behavior?

Allows downloads from SSL sites when using Haiku.

Are there any breaking changes? Will any existing behavior change?

Should not affect any other systems.

Anything else we should know?

Did you check all the boxes?

[X] Focus on a single fix or feature; remove any unrelated formatting or code changes
[X] Add unit tests showing fix or feature works; all tests pass
[X] Mention any related issues (put closes #XXXX in comment to auto-close issue when PR is merged)
[X] Follow our coding conventions
[X] Minimize the number of commits
[X] Align documentation to your changes

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premake / premake-core