t4200: convert sed expression which operates on non-text file to perl
t4200: convert sed expression which operates on non-text file to perl

POSIX only requires sed to work on text files and MERGE_RR is not a text
file.  Some versions of sed complain that this file is not newline
terminated, and exit non-zero.  Use perl instead which does not have a
problem with it.

Signed-off-by: Brandon Casey <77bc9a9984e6786c5799d7a71768cf023120ef76@nrlssc.navy.mil>
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