code formatting for transaction.cpp
code formatting for transaction.cpp

Summary: as title

Test Plan: make check

Reviewers: #bitcoin_abc, schancel, O1 Bitcoin ABC, jasonbcox

Reviewed By: #bitcoin_abc, O1 Bitcoin ABC, jasonbcox

Subscribers: teamcity

Differential Revision: https://reviews.bitcoinabc.org/D1626

Bitcoin-ABC/bitcoin-abc,Bitcoin-ABC/bitcoin-abc,Bitcoin-ABC/bitcoin-abc,cculianu/bitcoin-abc,cculianu/bitcoin-abc,ftrader-bitcoinabc/bitcoin-abc,Bitcoin-ABC/bitcoin-abc,ftrader-bitcoinabc/bitcoin-abc,ftrader-bitcoinabc/bitcoin-abc,cculianu/bitcoin-abc,Bitcoin-ABC/bitcoin-abc,Bitcoin-ABC/bitcoin-abc,ftrader-bitcoinabc/bitcoin-abc,ftrader-bitcoinabc/bitcoin-abc,Bitcoin-ABC/bitcoin-abc,cculianu/bitcoin-abc,ftrader-bitcoinabc/bitcoin-abc,ftrader-bitcoinabc/bitcoin-abc,Bitcoin-ABC/bitcoin-abc,Bitcoin-ABC/bitcoin-abc,cculianu/bitcoin-abc,ftrader-bitcoinabc/bitcoin-abc,ftrader-bitcoinabc/bitcoin-abc,ftrader-bitcoinabc/bitcoin-abc,cculianu/bitcoin-abc,Bitcoin-ABC/bitcoin-abc,Bitcoin-ABC/bitcoin-abc,Bitcoin-ABC/bitcoin-abc,cculianu/bitcoin-abc,Bitcoin-ABC/bitcoin-abc,cculianu/bitcoin-abc