Switch to new download format, update dependencies and source.sh script

pkg.info

@@ -1,10 +1,27 @@
 name: pam
 description: Pluggable Authentication Modules for Linux
 version: 1.7.1
+revision: 2
 url: https://github.com/linux-pam/linux-pam
 license: GPL2-or-later
 architecture: any
-depends: ["glibc","elogind","libnsl","libtirpc","libxcrypt","docbook-xsl-nons"]
-make_depends: ["flex","libxslt","meson"]
-keep: ["etc/environment"]
 type: source
+keep:
+  - etc/environment
+depends:
+  - glibc
+  - libelogind
+  - libnsl
+  - libtirpc
+  - libxcrypt
+  - docbook-xsl-nons
+make_depends:
+  - elogind
+  - flex
+  - libxslt
+  - meson
+downloads:
+  - url: https://github.com/linux-pam/linux-pam/releases/download/v${BPM_PKG_VERSION}/Linux-PAM-${BPM_PKG_VERSION}.tar.xz
+    extract_to: ${BPM_SOURCE}
+    extract_strip_components: 1
+    checksum: 21dbcec6e01dd578f14789eac9024a18941e6f2702a05cf91b28c232eeb26ab0