using only boost code headers

[koh-osug]

The build fails on Ubuntu 20.04-4 when compiling with:

undefined reference to boost::system::system_category()

The stack overflow solution fixes it.

[andrepuschmann]

Hey @koh-osug, thanks for the PR and please excuse the long delay in responding. Meanwhile we've double checked with Ubuntu 20.04-4 and also 22.04 and it compiles fine without it. Maybe it's only exposed under some conditions? Anyway, I'd leave the PR open in case someone has a similar issue and finds this useful. We are reconsidering it for inclusion when we have a better understanding in which cases it's needed. Thanks

[koh-osug]

I compiled it under an Atom based processor, maybe this is the important context.

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.

---

Karsten Ohme seems not to be a GitHub user. You need a GitHub account to be able to sign the CLA. If you have already a GitHub account, please add the email address used for this commit to your account.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}