t: improve the test-case for parse_names()

t: improve the test-case for parse_names()

In the existing test-case for parse_names(), the fact that empty
lines should be ignored is not obvious because the empty line is
immediately followed by end-of-string. This can be mistaken as the
empty line getting replaced by NULL. Improve this by adding a
non-empty line after the empty one to demonstrate the intended behavior.

Mentored-by: Patrick Steinhardt <ps@pks.im>
Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Chandra Pratap <chandrapratap3519@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>