send-email: accept --no-signed-off-by-cc as the documentation states

--no-signed-off-cc is still supported, for backwards compatibility

Signed-off-by: Eric Wong <normalperson@yhbt.net>
Signed-off-by: Junio C Hamano <junkio@cox.net>
diff --git a/git-send-email.perl b/git-send-email.perl
index b0d095b..7c8d512 100755
--- a/git-send-email.perl
+++ b/git-send-email.perl
@@ -54,7 +54,7 @@
 		    "compose" => \$compose,
 		    "quiet" => \$quiet,
 		    "suppress-from" => \$suppress_from,
-		    "no-signed-off-cc" => \$no_signed_off_cc,
+		    "no-signed-off-cc|no-signed-off-by-cc" => \$no_signed_off_cc,
 	 );
 
 # Now, let's fill any that aren't set in with defaults: