git-bisect-lk2009: update java code conventions link

git-bisect-lk2009: update java code conventions link

A reference to Java Code Conventions in git-bisect-lk2009.txt uses an
outdated URL that redirects to table of contents for the conventions.
The actual claim about "80%" that this reference backs up is on the
first page of the conventions:

  https://www.oracle.com/java/technologies/javase/codeconventions-introduction.html

Use this newer URL and its title in the reference.

Signed-off-by: Andrei Rybak <rybak.a.v@gmail.com>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>