t/t3437: fixup here-docs in the 'setup' test

t/t3437: fixup here-docs in the 'setup' test

The most common way to format here-docs in Git test scripts is for the
body and EOF to be indented the same amount as the command which opened
the here-doc. Fix a few here-docs in this script to conform to that
standard and also remove the unnecessary curly braces.

Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Mentored-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Charvi Mendiratta <charvi077@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>