only try to get ip address if necessary

he-ddns

@@ -50,6 +50,7 @@ done
 # shellcheck source=he-ddnsrc
 . "$config" || die $LINENO
 
+if [[ -n "${DOMAINS4[*]}" ]]; then
 	ipv4="$(curl -sSL4 "$ip_host")" || die $LINENO
 	for domain in "${!DOMAINS4[@]}"; do
 		printf "%s :: " "$domain"
@@ -57,7 +58,9 @@ for domain in "${!DOMAINS4[@]}"; do
 		curl -sSL4 "$url" -d "hostname=$domain" -d "password=$key" -d "myip=$ipv4" || die $LINENO
 		echo
 	done
+fi
 
+if [[ -n "${DOMAINS6[*]}" ]]; then
 	ipv6="$(curl -sSL6 "$ip_host")" || die $LINENO
 	for domain in "${!DOMAINS6[@]}"; do
 		printf "%s :: " "$domain"
@@ -65,3 +68,4 @@ for domain in "${!DOMAINS6[@]}"; do
 		curl -sSL6 "$url" -d "hostname=$domain" -d "password=$key" -d "myip=$ipv6" || die $LINENO
 		echo
 	done
+fi