t7401: change indentation for enhanced readability

t7401: change indentation for enhanced readability

Change the indentation of expected outputs for enhanced readability of
the tests. Also modify the heredoc string limiter in a test which lacks
it to support the indentation change.

Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Mentored-by: Kaartic Sivaraam <kaartic.sivaraam@gmail.com>
Helped-by: Junio C Hamano <gitster@pobox.com>
Helped-by: Taylor Blau <me@taylorr.com>
Signed-off-by: Shourya Shukla <shouryashukla.oo@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>