t0050-*.sh: mark the rename (case change) test as passing

t0050-*.sh: mark the rename (case change) test as passing

Since commit baa37bff ("mv: allow renaming to fix case on case
insensitive filesystems", 08-05-2014), the 'git mv' command has
been able to rename a file, to one which differs only in case,
on a case insensitive filesystem.

This results in the 'rename (case change)' test, which used to fail
prior to this commit, to now (unexpectedly) pass. Mark this test as
passing.

[jc: Ramsay's tests on Cygwin, Eric's on Mac OS X]

Signed-off-by: Ramsay Jones <redacted>
Tested-by: Eric Sunshine <redacted>
Signed-off-by: Junio C Hamano <redacted>