fix access violation in vector2.

include/assimp/vector2.h

@@ -85,7 +85,6 @@ public:
     const aiVector2t& operator /= (TReal f);
 
     TReal operator[](unsigned int i) const;
-    TReal& operator[](unsigned int i);
 
     bool operator== (const aiVector2t& other) const;
     bool operator!= (const aiVector2t& other) const;

include/assimp/vector2.inl

@@ -134,21 +134,6 @@ TReal aiVector2t<TReal>::operator[](unsigned int i) const {
     return x;
 }
 
-// ------------------------------------------------------------------------------------------------
-template <typename TReal>
-inline
-TReal& aiVector2t<TReal>::operator[](unsigned int i) {
-	switch (i) {
-		case 0:
-			return x;
-		case 1:
-			return y;
-		default:
-			break;
-    }
-    return x;
-}
-
 // ------------------------------------------------------------------------------------------------
 template <typename TReal>
 inline