Expand tab to spaces and and cleanup formatting

[aol-nnov]

This is a followup for https://github.com/pjsip/pjproject/pull/3292 and https://github.com/pjsip/pjproject/pull/3210 but regarding aconfigure.ac

[aol-nnov]

@sauwming I had a hard time modifying aconfigure.ac during my previous PRs, so I decided to remove mixed indentation in aconfigure.ac first and clean up the formatting. Let's review this and I'll redo my PR on top.

[jimying]

I think it should't format aconfigure which is generated by autoconf tool

[aol-nnov]

@jimying aconfigure was re-generated with autoconf. @sauwming told me to do so in other PRs where there are changes in aconfigure.ac, so, I did it in this PR, too.

[aol-nnov]

@sauwming is CI failing due to some enviromental issues?

I'm not convinced, that formatting led to

07:54:49.159   waiting for active NS to expire (20 sec)
07:55:09.282   failing server0

[jimying]

@jimying aconfigure was re-generated with autoconf. @sauwming told me to do so in other PRs where there are changes in aconfigure.ac, so, I did it in this PR, too.

ok, i advise use autoconf 2.71 to generate aconfigure to make less changes (Keep use the same autoconf version as before)

[aol-nnov]

@jimying unfortunately, autoconf 2.71 is not available in Debian 12 (current stable version of OS)

[jimying]

@jimying unfortunately, autoconf 2.71 is not available in Debian 12 (current stable version of OS)

@aol-nnov I have a debian 12 server, i check that it's autoconf version is 2.71, maybe you need run apt update

[aol-nnov]

@jimying sorry for inconvenience, it's Debian 11 here. We still need to build pjsp for that version of OS. If you insist, I'll regenerate with 2.71

[aol-nnov]

regenerated with autoconf 2.71