[Qt] take care of a missing typecast in PaymentRequestPlus::getMerchant()

src/qt/paymentrequestplus.cpp

@@ -166,9 +166,8 @@ bool PaymentRequestPlus::getMerchant(X509_STORE* certStore, QString& merchant) c
         EVP_MD_CTX_init(&ctx);
         if (!EVP_VerifyInit_ex(&ctx, digestAlgorithm, NULL) ||
             !EVP_VerifyUpdate(&ctx, data_to_verify.data(), data_to_verify.size()) ||
-            !EVP_VerifyFinal(&ctx, (const unsigned char*)paymentRequest.signature().data(), paymentRequest.signature().size(), pubkey)) {
-
-            throw SSLVerifyError("Bad signature, invalid PaymentRequest.");
+            !EVP_VerifyFinal(&ctx, (const unsigned char*)paymentRequest.signature().data(), (unsigned int)paymentRequest.signature().size(), pubkey)) {
+            throw SSLVerifyError("Bad signature, invalid payment request.");
         }
 
         // OpenSSL API for getting human printable strings from certs is baroque.