Deskflow: Clipboard receiver can accumulate data beyond Deskflow's configured clipboard size limit

Deskflow is a keyboard and mouse sharing app. From 1.17.0 until continuous build 1.26.0.300, a connected peer can send repeated DCLP DataChunk messages to ClipboardChunk::assemble() in src/lib/deskflow/ClipboardChunk.cpp, causing the server path in src/lib/server/ClientProxy1_6.cpp or client path in src/lib/client/ServerProxy.cpp to append data beyond the DataStart declared size and configured clipboard limit before DataEnd validation, exhausting receiver memory. This issue is fixed in continuous build 1.26.0.300.