Do not encode DEL (#115)

Author: mjethani

punycode.js

@@ -15,7 +15,7 @@ const delimiter = '-'; // '\x2D'
 
 /** Regular expressions */
 const regexPunycode = /^xn--/;
-const regexNonASCII = /[^\0-\x7E]/; // non-ASCII chars
+const regexNonASCII = /[^\0-\x7F]/; // Note: U+007F DEL is excluded too.
 const regexSeparators = /[\x2E\u3002\uFF0E\uFF61]/g; // RFC 3490 separators
 
 /** Error messages */