t4015: simplify sed command that is not even seen by sed
t4015: simplify sed command that is not even seen by sed

Noticed by Andreas Schwab; \<LF> inside a double quotes pair is
eaten by the shell to become an empty string and is not doing
anything.

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