Fix P300 magic card speller display

plugins/processing/simple-visualization/src/box-algorithms/CBoxAlgorithmP300MagicCardVisualization.cpp

@@ -59,7 +59,7 @@ bool CBoxAlgorithmP300MagicCardVisualization::initialize()
 	CString tcpTaggingHostPort    = FSettingValueAutoCast(*this->getBoxAlgorithmContext(), 6);
 	const CString bgImageFilename = FSettingValueAutoCast(*this->getBoxAlgorithmContext(), 7);
 
-	for (size_t i = 6; i < boxContext.getSettingCount(); ++i) {
+	for (size_t i = 8; i < boxContext.getSettingCount(); ++i) {
 		GError* error = nullptr;
 
 		CString fgImageFilename = FSettingValueAutoCast(*this->getBoxAlgorithmContext(), i);