Update package version to 2.6.4

source.sh

@@ -2,7 +2,7 @@
 # BPM Expects the source code to be extracted into the automatically created 'source' directory which can be accessed using $BPM_SOURCE
 # BPM Expects the output files to be present in the automatically created 'output' directory which can be accessed using $BPM_OUTPUT
 
-DOWNLOAD="https://prdownloads.sourceforge.net/expat/expat-${BPM_PKG_VERSION}.tar.xz"
+DOWNLOAD="https://github.com/libexpat/libexpat/releases/download/R_${BPM_PKG_VERSION//./_}/expat-${BPM_PKG_VERSION}.tar.gz"
 FILENAME="${DOWNLOAD##*/}"
 
 # The prepare function is executed in the root of the temp directory
@@ -32,4 +32,6 @@ check() {
 package() {
   make DESTDIR="$BPM_OUTPUT" install
   install -v -m644 doc/*.{html,css} "$BPM_OUTPUT"/usr/share/doc/expat
+
+  install -Dm644 COPYING "$BPM_OUTPUT"/usr/share/licenses/expat/COPYING
 }