[Qt] remove unused PaymentRequestPlus::getPKIType function

src/qt/paymentrequestplus.cpp

@@ -59,12 +59,6 @@ bool PaymentRequestPlus::IsInitialized() const
     return paymentRequest.IsInitialized();
 }
 
-QString PaymentRequestPlus::getPKIType() const
-{
-    if (!IsInitialized()) return QString("none");
-    return QString::fromStdString(paymentRequest.pki_type());
-}
-
 bool PaymentRequestPlus::getMerchant(X509_STORE* certStore, QString& merchant) const
 {
     merchant.clear();

src/qt/paymentrequestplus.h

@@ -29,7 +29,6 @@ public:
     bool SerializeToString(std::string* output) const;
 
     bool IsInitialized() const;
-    QString getPKIType() const;
     // Returns true if merchant's identity is authenticated, and
     // returns human-readable merchant identity in merchant
     bool getMerchant(X509_STORE* certStore, QString& merchant) const;