package/libxcrypt: fix legal info

package/libxcrypt: fix legal info

When the initial package has been submitted, the hashes for the
license files were computed against the files from the repository,
not the release tarball, but the files had changed in the repo
since the version was cut.

Fix that hash.

Fixes:
    http://autobuild.buildroot.net/results/206aac81799074ef45c0cc7b9979cbf02c3935d5
    http://autobuild.buildroot.net/results/8db5df1286673fdedb854bad2b9e5757d5218950

Signed-off-by: Guillaume W. Bres <guillaume.bressaix@gmail.com>
[yann.morin.1998@free.fr: expand commit log with root cause]
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>