[3.x][PHP8.5] Passing a string which is not a single byte to ord() is deprecated (#63)

https://wiki.php.net/rfc/deprecations_php_8_5#deprecate_passing_string_which_are_not_one_byte_long_to_ord

Author: heelc29

src/phputf8/ord.php

@@ -21,7 +21,7 @@
 */
 function utf8_ord($chr)
 {
-    $ord0 = ord($chr);
+    $ord0 = ord($chr[0]);
 
     if ($ord0 >= 0 && $ord0 <= 127) {
         return $ord0;