libnopoll: use xz compression rather than gz

Signed-off-by: John Clark inindev@gmail.com
Tested-by: John Clark inindev@gmail.com

libs/libnopoll/Makefile

@@ -15,7 +15,7 @@ PKG_SOURCE_PROTO:=git
 PKG_SOURCE_URL:=https://github.com/ASPLes/nopoll.git
 PKG_SOURCE_SUBDIR:=$(PKG_NAME)-$(PKG_VERSION)
 PKG_SOURCE_VERSION:=60a81fbd199551ac5dd017b9a44fb46e8530680b
-PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION)-$(PKG_SOURCE_VERSION).tar.gz
+PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION)-$(PKG_SOURCE_VERSION).tar.xz
 
 PKG_MAINTAINER:=John Clark <inindev@gmail.com>