Commit fb71f0d introduced to possibility to add options behind permissions

in fstab. Unfortunately it breaks scenarios where no options are provided
as the current regex expects the comma with the options always to be present.

This patch fixes the regex to handle the options as group.

usr/local/share/bastille/mount.sh

@@ -92,7 +92,7 @@ elif [ ! -e "${_hostpath}" ] || [ "${_type}" != "nullfs" ]; then
 fi
 
 # Mount permissions,options need to start with "ro" or "rw"
-if ! echo "${_perms}" | grep -Eq 'r[w|o],.*$'; then
+if ! echo "${_perms}" | grep -Eq 'r[w|o](,.*)?$'; then
     error_notify "Detected invalid mount permissions in FSTAB."
     warn "Format: /host/path /jail/path nullfs ro 0 0"
     warn "Read: ${_fstab}"