We do not support sprout privkeys that begin with SK

src/mainwindow.cpp

@@ -1150,7 +1150,7 @@ void MainWindow::doImport(QList<QString>* keys) {
     QString key = keys->takeFirst();
 
     bool rescan = false;
-    if (key.startsWith("SK") || Settings::getInstance()->isValidSaplingPrivateKey(key) ) {
+    if (Settings::getInstance()->isValidSaplingPrivateKey(key) ) {
         DEBUG("importing zaddr privkey with rescan=" << rescan);
         rpc->importZPrivKey(key, rescan, [=] (auto) { this->doImport(keys); });
     } else {