LICENSE: Update to match Index Data's online Revised BSD license

[hughmcmaster]

When packaging a new version of YAZ for Debian, I noticed the LICENSE file refers to "Regents", as in the original BSD-3-clause licence from UCB.

This patch:

• Extends copyright to 2024.
• Replaces 'Regents' with 'Index Data'.
• Adds whitespace for readability.
• Wraps lines as needed.