Fix fluctuating "Broadhash consensus"

[simonmorgenthaler]

"Broadhash consensus" seems to fluctuate very much between 1% and 50%. If you are unlucky and you have a consensus of <10% at the time you should forge a block, you'll miss that block.
It happens quite often for me.

The syncing mechanism doesn't fail and the node doesn't fork.

[karmacoma]

@simonmorgenthaler Thanks, working on it with priority. @Isabello debugged the code and we should have it fixed asap.