Replace deprecated sys_siglist with strsignal

[tgurr]

Required to work with glibc >= 2.32.

https://sourceware.org/pipermail/libc-announce/2020/000029.html

The deprecated arrays sys_siglist, _sys_siglist, and sys_sigabbrev
are no longer available to newly linked binaries, and their declarations
have been removed from <string.h>. They are exported solely as
compatibility symbols to support old binaries. All programs should use
strsignal instead.

What: N/A

Why: #1279

How: N/A

Checklist:

• Tests
• CHANGELOG Entry

[mattmundell]

Thanks.

If you want this in the next 20.08 release then please submit a PR against gvmd-20.08 instead.

And would be great if you could add a CHANGELOG.md entry.

[tgurr]

If you want this in the next 20.08 release then please submit a PR against gvmd-20.08 instead.

I'll open a follow-up PR once this is through.

And would be great if you could add a CHANGELOG.md entry.

Added.

[mattmundell]

If you want this in the next 20.08 release then please submit a PR against gvmd-20.08 instead.

I'll open a follow-up PR once this is through.

And would be great if you could add a CHANGELOG.md entry.

Added.

[mattmundell]

I'll open a follow-up PR once this is through.

I think just gvmd-20.08 would be easier, because we'll merge that to master.

[tgurr]

I'll open a follow-up PR once this is through.

I think just gvmd-20.08 would be easier, because we'll merge that to master.

Took me a moment to figure out, I hope I did everything correctly switching the PR to gvmd-20.08.

[mattmundell]

Yes, that's great, thank you.

One nitpick left, just noticed the missing spaces.