miss using when exporting UnityEngine.UI

[c3076802]

Fix

    public static string _C(string str)
{
...
            if (str.Length > 12 && str.Substring(0, 12) == "UnityEngine.")
            {
                if (nameSpace == "UnityEngine")
                {
                    usingList.Add("UnityEngine");                    
                }
                if (nameSpace == "UnityEngine.UI")
                {
                    usingList.Add("UnityEngine.UI");
                    usingList.Add("UnityEngine");
                }
...
}