cmake: remove dead file

app/gui/CMakeLists.txt

@@ -3,7 +3,7 @@ project(irritator-gui VERSION 0.1.0 LANGUAGES CXX)
 
 set(gui_sources
     application.cpp application.hpp dialog.cpp dialog.hpp imnodes.cpp
-    imnodes.hpp implot.h implot.cpp internal.hpp internal.cpp node-editor.hpp
+    imnodes.hpp implot.h implot.cpp internal.hpp internal.cpp
     node-editor.cpp simulation-editor.cpp sources.cpp window-logger.cpp
     ${PROJECT_SOURCE_DIR}/../../external/imgui/imgui.cpp
     ${PROJECT_SOURCE_DIR}/../../external/imgui/imgui.h