tag: duplicate mention of --contains should mention --no-contains

Fix a duplicate mention of --contains in the SYNOPSIS to mention
--no-contains.

This fixes an error introduced in my commit ac3f5a3468 ("ref-filter:
add --no-contains option to tag/branch/for-each-ref", 2017-03-24).

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-tag.txt

@@ -12,7 +12,7 @@ SYNOPSIS
 'git tag' [-a | -s | -u <keyid>] [-f] [-m <msg> | -F <file>]
 	<tagname> [<commit> | <object>]
 'git tag' -d <tagname>...
-'git tag' [-n[<num>]] -l [--contains <commit>] [--contains <commit>]
+'git tag' [-n[<num>]] -l [--contains <commit>] [--no-contains <commit>]
 	[--points-at <object>] [--column[=<options>] | --no-column]
 	[--create-reflog] [--sort=<key>] [--format=<format>]
 	[--[no-]merged [<commit>]] [<pattern>...]