change scheme value from uppercase to lowercase

templates/answerfile.j2

@@ -10,7 +10,7 @@ export TIMEZONE="{{ hostobj.timezone | default("GMT") }}"
 {% set disks = [] %}
 {% for disk in hostobj.disks %}
 {%   do disks.append('"%s"' | format(disk.device)) %}
-{{   'export DISK_%s_SCHEME="%s"' | format(disk.device | upper, disk.scheme | upper) }}
+{{   'export DISK_%s_SCHEME="%s"' | format(disk.device | upper, disk.scheme | lower) }}
 {%   if 'partitions' in disk %}
 {{     'declare -a DISK_%s_PARTITIONS=()' | format(disk.device | upper) }}
 {%     for part in disk.partitions %}