[packages/libidn2] Use lua in %post scripts to break dependency loop

[Jacek Konieczny]

On 19/02/2019 15.23, glen wrote:
> the behaviour is not identical:
> 
> 1. previous code did not hide ldconfig errors

Which should not bother us. Even if ldconfig does not work we need this
installed if we want glibc installed properly

> 2. previous code skipped invocation if /usr/sbin/fix-info-dir was missing

Not needed here – we can just ignore the errors.

> as you hopefully tested this, then os.execute does not trigger failure,

> but would be nice to see ldconfig errors, if any.

Maybe…

Anyway… that change was pointless, as a loop is still there, although
shorter (libidn2 -> glibc -> libidn2) and not easy to fix.

Adding external libidn2 dependency to glibc was a very bad idea and
should be reverted. glibc must not have any 'heavy' external
dependencies. And libidn2 is not even a single library, as it pulls
libunistring.


Jacek