Documentation: Strip texinfo anchors to avoid duplicates

This keeps texinfo 5.x happy. See https://bugs.gentoo.org/464210.

Signed-off-by: Martin von Gagern <Martin.vGagern@gmx.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/cat-texi.perl

@@ -12,6 +12,7 @@ while (<STDIN>) {
 		push @menu, $1;
 	}
 	s/\(\@pxref{\[(URLS|REMOTES)\]}\)//;
+	s/\@anchor\{[^{}]*\}//g;
 	print TMP;
 }
 close TMP;