Nav: NavScoreItem uses g.CurrentWindow and not g.NavWindow. This was changed as part of b3cba62b80 when first trying to implement the NavFlattenedFlag. As it turns out we won't need it. Committing separately for safety. (#787)

imgui.cpp

@@ -2135,7 +2135,7 @@ static float NavScoreItemDistInterval(float a0, float a1, float b0, float b1)
 static bool NavScoreItem(ImGuiNavMoveResult* result, ImRect cand)
 {
     ImGuiContext& g = *GImGui;
-    ImGuiWindow* window = g.NavWindow;
+    ImGuiWindow* window = g.CurrentWindow;
     if (g.NavLayer != window->DC.NavLayerCurrent)
         return false;