erp5_wechat_secure_payment: possible to define custom base_url

fix also can't get parameter thought request for current url format

bt5/erp5_wechat_secure_payment/DocumentTemplateItem/portal_components/document.erp5.WechatService.py

@@ -248,10 +248,10 @@ class WechatService(XMLObject):
           'In Navigate', error=False)
 
     portal = self.getPortalObject()
-    base_url = portal.absolute_url()
+    base_url = wechat_dict.pop('base_url', '%s/#wechat_payment' % portal.absolute_url())
 
     return self.REQUEST.RESPONSE.redirect(
-      "%s/#wechat_payment?trade_no=%s&price=%s&payment_url=%s" % (
+      "%s?trade_no=%s&price=%s&payment_url=%s" % (
         base_url,
         wechat_dict['out_trade_no'],
         wechat_dict['total_fee'],