devel/indi: update 2.1.1 → 2.1.2.1, improve port

Changelogs:
https://github.com/indilib/indi/releases/tag/v2.1.2
https://github.com/indilib/indi/releases/tag/v2.1.2.1

Improve port:

• add category astro;
• add https://www.indilib.org/ to WWW;
• add LICENSE_FILE;
• parametrize so version in plist;
• improve description.

PR: 284742
Approved by: acm (maintainer, timeout > 1 month)