Update glTFAsset.inl

closes https://github.com/assimp/assimp/issues/893: fix invalid memcpy usage.

code/glTFAsset.inl

@@ -288,7 +288,7 @@ inline void Buffer::Read(Value& obj, Asset& r)
             }
 
             this->mData.reset(new uint8_t[dataURI.dataLength]);
-            memcmp(dataURI.data, this->mData.get(), dataURI.dataLength);
+            memcpy( this->mData.get(), dataURI.data, dataURI.dataLength );
         }
     }
     else { // Local file