[rbp] We require the pixels in non-reencoding texture caching

If the direct texture reencode path fails, we do a seperate jpeg decode then encode path, which always fails as the pixels are not available.
Make sure we set the require pixels flag in this case
Merge pull request #3968 from popcornmix/require_pix

[rbp] We require the pixels in non-reencoding texture caching