Improve _htmlEscape function robustness by using printf instead of echo

small commit to trigger github actions

dnsapi/dns_inwx.sh

@@ -172,10 +172,10 @@ _inwx_check_cookie() {
 
 _htmlEscape() {
   _s="$1"
-  _s=$(echo "$_s" | sed "s/&/&/g")
-  _s=$(echo "$_s" | sed "s/</\&lt;/g")
-  _s=$(echo "$_s" | sed "s/>/\&gt;/g")
-  _s=$(echo "$_s" | sed 's/"/\&quot;/g')
+  _s=$(printf '%s' "$_s" | sed "s/&/&amp;/g")
+  _s=$(printf '%s' "$_s" | sed "s/</\&lt;/g")
+  _s=$(printf '%s' "$_s" | sed "s/>/\&gt;/g")
+  _s=$(printf '%s' "$_s" | sed 's/"/\&quot;/g')
   printf -- %s "$_s"
 }