fix: Restore clipboard sharing after 53441821e0

We wanted the value contained in the string as size_t, not the size (length) of
the string. size_t is (normally) an alias for unsigned long, so toUlong() should
do the trick.

src/lib/deskflow/ClipboardChunk.cpp

@@ -74,7 +74,7 @@ ClipboardChunk::assemble(deskflow::IStream *stream, std::string &dataCached, Cli
   }
 
   if (mark == ChunkType::DataStart) {
-    s_expectedSize = QString::fromStdString(data).size();
+    s_expectedSize = QString::fromStdString(data).toULong();
     LOG_DEBUG("start receiving clipboard data");
     dataCached.clear();
     return Started;