paypro: fix chain validation for browser.

lib/browser/PayPro.js

@@ -103,7 +103,7 @@ PayPro.prototype.x509Verify = function(key) {
     var data = new Buffer(nder, 'hex');
     var nc = rfc3280.Certificate.decode(data, 'der');
     var npubKey = nc.tbsCertificate.subjectPublicKeyInfo.subjectPublicKey.data;
-    npubKey = self._DERtoPEM(npubKey, 'RSA PUBLIC KEY');
+    npubKey = KJUR.asn1.ASN1Util.getPEMStringFromHex(npubKey, 'RSA PUBLIC KEY');
 
     // Get signature from current certificate:
     var data = new Buffer(der, 'hex');