Speedup by disabling temporaty sanity check

The sanity check slows down loading document > 100 pages.
It is very very very very slow for document that have more then > 400 pages
Instead of over a minute for layouting it is not done in 4 seconds for the 800 pages ODF spec.

During my tests I only found one document triggering an assert inside the sanity check.
It can be downloaded from