Remove the workaround that lowers fees for transfering via contracts module

[pepyakin]

If #4147 is merged, then we will have a workaround that will make transfers via contracts module much more cheaper than through balances module.

See this

[athei]

What is to be done here after the merge of #5712? Do we need to adjust the Schedule?

[athei]

AFAIK that workaround never made it in because #4147 was never merged. Instead, #5446 was merged with does not contain such a work around.