window: do not draw anything on a created window

this makes it so the window doesn't blink right after creation

src/window.c

@@ -239,11 +239,6 @@ GLFWAPI GLFWwindow* glfwCreateWindow(int width, int height,
         return NULL;
     }
 
-    // Clearing the front buffer to black to avoid garbage pixels left over
-    // from previous uses of our bit of VRAM
-    glClear(GL_COLOR_BUFFER_BIT);
-    _glfwPlatformSwapBuffers(window);
-
     // Restore the previously current context (or NULL)
     _glfwPlatformMakeContextCurrent(previous);