C++: fix parser bug in structured logic

The bug was already fixed in the parseonly code, but not in the
generic structured code.

cpp/src/monoformat_structured.cpp

@@ -1513,6 +1513,9 @@ std::expected<std::unique_ptr<ClippedTextElement>, ParseError> ClippedTextElemen
         return std::unexpected(textLength.error());
     }
     std::size_t alignedRoundedUp = (*textLength + 2 + 4 - 1) / 4 * 4 - 2;
+    if (formatVersion >= 2) {
+        alignedRoundedUp = (*textLength + 4 - 1) / 4 * 4;
+    }
     auto textData = readBuffer(buffer, alignedRoundedUp);
     if (!textData) {
         return std::unexpected(textData.error());