It seems that the selective block update, i.e., update of the blocks
which have been (de)refined only, is not perfect. It violates the
numerical conservation somehow, and requires more investigation.
In order to fix this, perform the update of all data blocks, no matter
if they were refined or not. This makes some blocks to be updated twice,
but resolves the problem of variable conservation.
Signed-off-by: Grzegorz Kowal <grzegorz@amuncode.org>