add workaround for rar on arm

fail2ban/update.sh

@@ -1,3 +1,3 @@
-for file in $(ls *-v2.sh) ; do
-  cp -- "${file}" "$(echo "${file}" | sed -e 's/v2\.sh/v3\.sh/')"
+for file in $(ls *-v3.sh) ; do
+  cp -- "${file}" "$(echo "${file}" | sed -e 's/v3\.sh/v4\.sh/')"
 done