Nits in src/qt/init.cpp

Summary: Fix control flow and stylistic nits in qt/init.cpp

Test Plan:

make VERBOSE=1 check

Launch the QT GUI

Reviewers: #bitcoin_abc, Fabien, schancel

Reviewed By: #bitcoin_abc, Fabien

Subscribers: teamcity

Differential Revision: https://reviews.bitcoinabc.org/D2134