fix for issue 4972; error can not get domain token entry

acme.sh

@@ -4690,7 +4690,7 @@ $_authorizations_map"
         _debug keyauthorization "$keyauthorization"
       fi
 
-      entry="$(echo "$response" | _egrep_o '[^\{]*"type":"'$vtype'"[^\}]*')"
+      entry="$(echo "$response" | sed -n 's#"challenges":\[\([^]]*\)\]#\1#p' | sed 's#\(\}\),\({\)#\1\n\2#' | grep '"type":"'$vtype'"')"
       _debug entry "$entry"
 
       if [ -z "$keyauthorization" -a -z "$entry" ]; then