Fix some qt6 compile error

src/KBlocksNetClient.cpp

@@ -44,7 +44,11 @@ bool KBlocksNetClient::parseIPString(const QString &input, QHostAddress *ip, qui
 {
     bool result = false;
     ip->setAddress(input.left(input.indexOf(QStringLiteral(":"))));
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
     *port = input.midRef(input.indexOf(QStringLiteral(":")) + 1).toUInt(&result);
+#else
+    *port = QStringView(input).mid(input.indexOf(QStringLiteral(":")) + 1).toUInt(&result);
+#endif
     return result;
 }
 

src/KBlocksNetServer.cpp

@@ -435,7 +435,11 @@ bool KBlocksNetServer::parseIPString(const QString &input, QHostAddress *ip, qui
 {
     bool result = false;
     ip->setAddress(input.left(input.indexOf(QStringLiteral(":"))));
+#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
     *port = input.midRef(input.indexOf(QStringLiteral(":")) + 1).toUInt(&result);
+#else
+    *port = QStringView(input).mid(input.indexOf(QStringLiteral(":")) + 1).toUInt(&result);
+#endif
     return result;
 }