Don't reset the scroll layer if it is not being used

SimplyMenu does not use the scroll layer, therefore resetting the scroll
layer will break SimplyMenu scrolling due to the scroll layer taking
over the click config. Add a SimplyWindow boolean property that
explicitly specifies whether the scroll layer is used in order to avoid
resetting and applying the scroll layer click config if it is not used.

src/simply/simply_stage.c

@@ -501,6 +501,7 @@ static void window_load(Window *window) {
   *(void**) layer_get_data(layer) = self;
   layer_set_update_proc(layer, layer_update_callback);
   scroll_layer_add_child(self->window.scroll_layer, layer);
+  self->window.use_scroll_layer = true;
 }
 
 static void window_appear(Window *window) {

src/simply/simply_ui.c

@@ -381,6 +381,7 @@ static void window_load(Window *window) {
   *(void**) layer_get_data(layer) = self;
   layer_set_update_proc(layer, layer_update_callback);
   scroll_layer_add_child(self->window.scroll_layer, layer);
+  self->window.use_scroll_layer = true;
 
   simply_ui_set_style(self, 1);
 }

src/simply/simply_window.c

@@ -92,7 +92,7 @@ static void prv_set_scroll_layer_click_config(SimplyWindow *self) {
 
 void simply_window_set_scrollable(SimplyWindow *self, bool is_scrollable, bool animated,
                                   bool reset) {
-  if (self->is_scrollable == is_scrollable && !reset) { return; }
+  if (!self->use_scroll_layer || (self->is_scrollable == is_scrollable && !reset)) { return; }
 
   self->is_scrollable = is_scrollable;
 

src/simply/simply_window.h

@@ -24,6 +24,7 @@ struct SimplyWindow {
   ButtonId button_mask:4;
   GColor8 background_color;
   bool is_scrollable:1;
+  bool use_scroll_layer:1;
   bool use_status_bar:1;
   bool use_action_bar:1;
 #if defined(PBL_ROUND)