Test nix build change

Author: kieranjazy

flake.nix

@@ -22,7 +22,7 @@
 
     demos.chat-client.conf = ./demos/chat-client/Enarx.toml;
 
-    demos.chat-client.cpp.src = ./demos/chat-client/c++/main.cpp;
+    demos.chat-client.cpp.src = ["./demos/chat-client/c++/main.cpp", "./demos/chat-client/c++/assets.h"];
     demos.chat-client.rust.src = ./demos/chat-client/rust;
     demos.chat-client.rust.package = cargoPackage ./demos/chat-client/rust/Cargo.toml;