send-email: use \E***\Q instead of \*\*\*

Change the regex introduced in a03bc5b to use the \E...\Q escape
syntax instead of using backslashes. It's more readable like this, and
easier to grep for.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.comReviewed-by: Avery Pennarun <apenwarr@gmail.com>
Reviewed-by: Jeff King <peff@peff.net>
>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

git-send-email.perl

@@ -705,7 +705,7 @@ sub file_declares_8bit_cte {
 
 if (!$force) {
 	for my $f (@files) {
-		if (get_patch_subject($f) =~ /\*\*\* SUBJECT HERE \*\*\*/) {
+		if (get_patch_subject($f) =~ /\Q*** SUBJECT HERE ***\E/) {
 			die "Refusing to send because the patch\n\t$f\n"
 				. "has the template subject '*** SUBJECT HERE ***'. "
 				. "Pass --force if you really want to send.\n";