t0050: honor CASE_INSENSITIVE_FS in add (with different case)
t0050: honor CASE_INSENSITIVE_FS in add (with different case)

The test case "add (with different case)" indicates a
known breakage when run on a case insensitive file system.

The test is invalid for case sensitive file system, it will always fail.

Check the precondition CASE_INSENSITIVE_FS before running it.

Signed-off-by: Torsten Bögershausen <955341c97b9d93a23c19524fc0105a6405902afe@web.de>
Signed-off-by: Junio C Hamano <a6723cc3f76163bf7adb636a73ac3b0ceb3e6b9b@pobox.com>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git