libpth: fix license info

NEWS states:
* Change license from LGPLv3+/GPLv2+ to LGPLv2+.

Fixes:
http://autobuild.buildroot.net/results/bef/bef969ede5fc792b0a03f5669071600a0f746a7a/
http://autobuild.buildroot.net/results/2d5/2d59b8e6d69b70c621ff2031a9c4fd9e67ef13cf/
http://autobuild.buildroot.net/results/631/6318505c8e293e6c00b20eec39d851d0d15f6fec/

[Peter: also adjust _LICENSE, extend commit message]
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/libnpth/libnpth.mk

@@ -7,8 +7,8 @@
 LIBNPTH_VERSION = 1.5
 LIBNPTH_SOURCE = npth-$(LIBNPTH_VERSION).tar.bz2
 LIBNPTH_SITE = https://www.gnupg.org/ftp/gcrypt/npth
-LIBNPTH_LICENSE = LGPL-3.0+ or GPL-2.0+
-LIBNPTH_LICENSE_FILES = COPYING COPYING.LESSER
+LIBNPTH_LICENSE = LGPL-2.0+
+LIBNPTH_LICENSE_FILES = COPYING.LIB
 LIBNPTH_INSTALL_STAGING = YES
 
 $(eval $(autotools-package))