main: Update hash counter to update hash count appropriately to a single sha3
main: Update hash counter to update hash count appropriately to a single sha3

Summary: The existing hash counter increments by 2 to account for a double round of sha256

Reviewers: johann, ben

Reviewed By: ben

Differential Revision: https://phabricator.bitgo.com/D4853

BitGo/prova,BitGo/prova