PdfProcessor: Throw exception for encrypted/password protected files

cli/pdfprocessor.cpp

@@ -13,6 +13,11 @@ QVector<PageData> PdfProcessor::process(const QByteArray &data) const
 	{
 		throw QSSGeneralException("Failed to process pdf data");
 	}
+	if(doc->isEncrypted() || doc->isLocked())
+	{
+		throw QSSGeneralException("Doc is encrypted/locked");
+	}
+
 	QRectF entirePage;
 
 	auto pagecount = doc->numPages();