- clear the buffer for the cutscene textures when starting a new cutscene.

Otherwise the first frame may display garbage.

source/common/textures/animtexture.cpp

@@ -46,6 +46,7 @@ void AnimTexture::SetFrameSize(int  format, int width, int height)
 {
     FTexture::SetSize(width, height);
     Image.Resize(width * height * (format == Paletted ? 1 : 3));
+    memset(Image.Data(), 0, Image.Size());
     pixelformat = format;
 }