Fix NullWindow going white

src/text_editor/text_editor.cpp

@@ -694,7 +694,7 @@ void Update(Event event) {
             };
             for (int i = 1; i < Lengthof(id); i += 1) {
                 if (ActiveWindowID == id[i]) {
-                    for (int j = 0; j < Lengthof(id); j += 1) {
+                    for (int j = 1; j < Lengthof(id); j += 1) {
                         if (i == j) continue;
                         Window *window = GetWindow(id[j]);
                         window->visible = false;