unzip: Fix LICENSE

The contents of the LICENSE file included in the current source code
package match those of Info-ZIP license, which seems to originate from
the year 2009:

  This is version 2009-Jan-02 of the Info-ZIP license.

(From OE-Core rev: e7c9368e56a6ad90b4ffbba1b765e2b3a331c796)

(From OE-Core rev: 33e92e85b1632e933c3099a45ba53c6904eb6b88)

Signed-off-by: Niko Mauno <niko.mauno@vaisala.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Steve Sakoman <steve@sakoman.com>