Added architecture specifier in sources.list

preseed/lip-early.sh

 #!/bin/sh
 sed -i -e '/ubuntu\.com/d' -e '/^$/d' /root/etc/apt/sources.list
-echo "deb [ trusted=yes ] file:///isodevice/archives bionic lip" >> /root/etc/apt/sources.list
+echo "deb [ arch=amd64 trusted=yes ] file:///isodevice/archives bionic lip" >> /root/etc/apt/sources.list
 echo "deb http://ftp.halifax.rwth-aachen.de/ubuntu/ bionic main restricted universe multiverse" >> /root/etc/apt/sources.list
 echo "deb http://ftp.halifax.rwth-aachen.de/ubuntu/ bionic-security main restricted universe multiverse" >> /root/etc/apt/sources.list
 echo "deb http://ftp.halifax.rwth-aachen.de/ubuntu/ bionic-updates main restricted universe multiverse" >> /root/etc/apt/sources.list

scripts/liprepoctl.sh

@@ -11,7 +11,7 @@ DIST_VERSION=$DISTRIB_RELEASE
 function install_repo()
 {
 	echo "# offline repository of the linux install party
-deb [ trusted=yes ] file://$1/archives $DIST_CODENAME lip" > "$FILENAME"
+deb [ arch=amd64 trusted=yes ] file://$1/archives $DIST_CODENAME lip" > "$FILENAME"
 }
 
 function uninstall_repo()