Remove GLAD stuff

Author: petterarvidsson

src/main.cpp

@@ -1,19 +1,3 @@
-#if defined(NANOGUI_GLAD)
-    #if defined(NANOGUI_SHARED) && !defined(GLAD_GLAPI_EXPORT)
-        #define GLAD_GLAPI_EXPORT
-    #endif
-
-    #include <glad/glad.h>
-#else
-    #if defined(__APPLE__)
-        #define GLFW_INCLUDE_GLCOREARB
-    #else
-        #define GL_GLEXT_PROTOTYPES
-    #endif
-#endif
-
-#include <GLFW/glfw3.h>
-
 #include <nanogui/nanogui.h>
 
 #if defined(WIN32)