staking2.py consistently fails

[SkidanovAlex]

staking2.py was failing since around 7283fb2, due to incorrect node configuration. staking_repro* tests were not failing after that commit.
It is fixed in 1eb31

However, shortly before that fix staking_repro* tests started failing, it appears that they started failing after 613953.
After the fix for staking2.py I mentioned above, staking2.py is still consistently failing, but now due to a reason similar to staking_repro* tests.

The tests run short epochs, and in each epoch send "fake" staking txs early in the epoch, and then "real" staking txs late in the epoch (and thus "real" txs overwrite the "fake" txs). Both staking2.py and the staking_repro* tests seem to fail by accepting the "fake" staking tx, which usually happens if the "real" tx is not processed in time.

Given the timing of the failures starting, it is likely that slower get_status results in the delay in txs processing. Potentially disabling validity checks in those tests (if that's possible) or increasing the block timeout can help.