Only run lsb_release if exists

Author: tonyhb

modules/setup-systemd-resolved/setup-systemd-resolved

@@ -98,7 +98,7 @@ function configure_systemd_resolved {
   local -r consul_ip="$2"
   local -r consul_port="$3"
 
-  UBUNTU_VERSION=`lsb_release -s -r`
+  UBUNTU_VERSION=`lsb_release && lsb_release -s -r`
   if [ "$UBUNTU_VERSION" == "18.04" ] || [ "$UBUNTU_VERSION" == "20.04" ]; then
     log_info "Configuring systemd-resolved to forward lookups of the '$consul_domain' domain to $consul_ip:$consul_port in $CONSUL_DNS_MASQ_CONFIG_FILE"