execute gethostbyname() in the Tracer constructor is not optimal

[jackwoods]

Suggestion: can set via config.
If not set, then call this function (maybe not to call it by default).

[sergeyklay]

Hi @jackwoods!

Thank you for pointing out the use of gethostbyname() in the Tracer constructor. We value your insights in optimizing and enhancing the project.

As you might be aware, jaeger-client-php is an open-source project, with many of us contributing on a voluntary basis in our spare time. I'd be grateful if you could take a more active role in improving this part of the code.

If you're up for it, it would be great if you could submit a pull request with your proposed fix. Please ensure that your change maintains backward compatibility for existing users and that it's covered by tests. This helps us ensure the library's stability and reliability for all users.

Thanks again for your feedback, and we look forward to your continued involvement in the project!

[jackwoods]

Will try, thanks!