ReleaseChannel: don't offer 64-bit assets on 32-bit Windows

The old downloadMatchesCurrentOS() had an explicit 32-bit branch that
only accepted "32bit" assets. Restore that guard: 32-bit Windows builds
return no match instead of being offered the 64-bit Win10 installer that
won't run.

cockatrice/src/client/network/update/client/release_channel.cpp

@@ -68,6 +68,12 @@ void ReleaseChannel::checkForUpdates()
 // Find assets compatible with host platform (Linux is not supported by in-client updater)
 std::optional<int> ReleaseChannel::getTargetVersionForCurrentOS(const QString &fileName)
 {
+#if defined(Q_OS_WIN) && Q_PROCESSOR_WORDSIZE == 4
+    // The published Windows assets are 64-bit only
+    Q_UNUSED(fileName);
+    return std::nullopt;
+#endif
+
     const QRegularExpression *regex = nullptr;
 
     static const std::optional<int> systemVersion = getProductVersionMajor();