Update WXPay_CN.md

doc/WXPay_CN.md

@@ -10,7 +10,7 @@ fluwx.pay( appId: 'wxd930ea5d5a258f4f',
                   prepayId: '1101000000140415649af9fc314aa427',
                   packageValue: 'Sign=WXPay',
                   nonceStr: '1101000000140429eb40476f8896f4c9',
-                  timeStamp: '1398746574',
+                  timeStamp: 1398746574,
                   sign: '7FFECB600D7157C5AA49810D2D8F28BC2811827B',
                   signType: '选填',
                   extData: '选填'