[Qt] update a translation string and argument counts

Rebased-From: 643415aade
Github-Pull: #5583

src/qt/paymentserver.cpp

@@ -667,8 +667,7 @@ void PaymentServer::netRequestFinished(QNetworkReply* reply)
 
     // BIP70 DoS protection
     if (reply->size() > BIP70_MAX_PAYMENTREQUEST_SIZE) {
-        QString msg = tr("Payment request %2 is too large (%3 bytes, allowed %4 bytes).")
+        QString msg = tr("Payment request %1 is too large (%2 bytes, allowed %3 bytes).")
-            .arg(__func__)
             .arg(reply->request().url().toString())
             .arg(reply->size())
             .arg(BIP70_MAX_PAYMENTREQUEST_SIZE);