A pack of nits for rpcwallet.cpp
Summary: Mostly braces, but a few other minor changes as well.
Test Plan:
make check ../qa/pull-tester/rpc-tests.py
Reviewers: freetrader, CCulianu, #bitcoin_abc
Reviewed By: CCulianu, #bitcoin_abc
Differential Revision: https://reviews.bitcoinabc.org/D454