Examples: OpenGL2+GLFW/SDL: Added commented out glUseProgram(0) in main.cpp for visibility (#1116)

examples/opengl2_example/main.cpp

@@ -77,6 +77,7 @@ int main(int, char**)
         glViewport(0, 0, display_w, display_h);
         glClearColor(clear_color.x, clear_color.y, clear_color.z, clear_color.w);
         glClear(GL_COLOR_BUFFER_BIT);
+        //glUseProgram(0); // You may want this if using this code in an OpenGL 3+ context where shaders may be bound
         ImGui::Render();
         glfwSwapBuffers(window);
     }