[visual-studio-code-bin] Fix WMClass for Wayland

Apparently it's case-insensitive under X, but case-sensitive under
Wayland.

visual-studio-code.desktop

@@ -6,7 +6,7 @@ Exec=/opt/visual-studio-code/code --no-sandbox --unity-launch %F
 Icon=visual-studio-code
 Type=Application
 StartupNotify=false
-StartupWMClass=code
+StartupWMClass=Code
 Categories=Utility;TextEditor;Development;IDE;
 MimeType=text/plain;inode/directory;application/x-visual-studio-code-workspace;
 Actions=new-empty-window;