git fetch: Take '-n' to mean '--no-tags'

Prior to commit 8320199 (Rewrite builtin-fetch option parsing to use parse_options().), we understood '-n' as a short option to mean "don't fetch tags from the remote". This patch reinstates behaviour similar, but not identical to the pre commit 8320199 times. Back then, -n always overrode --tags, so if both --tags and -n was given on command-line, no tags were fetched regardless of argument ordering. Now we use a "last entry wins" strategy, so '-n --tags' means "fetch tags". Since it's patently absurd to say both --tags and --no-tags, this shouldn't matter in practice. Spotted-by: Artem Zolochevskiy <azol@altlinux.org> Reported-by: Dmitry V. Levin <ldv@altlinux.org> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Tested-by: Andreas Ericsson <ae@op5.se> Signed-off-by: Junio C Hamano <gitster@pobox.com>