Fixed #17, #20

Removed a global callback, raised by mypark#17

lib/apn.js

@@ -60,7 +60,7 @@ var Connection = function (optionArgs) {
 		if (!self.openingSocket) {
 			process.nextTick(function () {
 				self.socket = tls.connect(options['port'], options['gateway'], socketOptions,
-					callback = function () {
+					function () {
 						if (!self.socket.authorized) {
 							throw self.socket.authorizationError;
 						}