tag: fix typo in nested tagging hint

In eea9c1e7 (tag: advise on nested tags, 2019-04-04), tag was taught
to hint at the user if a nested tag is made. However, this message had a
typo and it said "The object referred to by your new is...", which was
missing a "tag" after "new". Fix this message by adding the "tag".
Signed-off-by: NDenton Liu <liu.denton@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

builtin/tag.c

@@ -207,7 +207,7 @@ struct create_tag_options {
 };
 
 static const char message_advice_nested_tag[] =
-	N_("You have created a nested tag. The object referred to by your new is\n"
+	N_("You have created a nested tag. The object referred to by your new tag is\n"
 	   "already a tag. If you meant to tag the object that it points to, use:\n"
 	   "\n"
 	   "\tgit tag -f %s %s^{}");

t/t7004-tag.sh

@@ -1702,7 +1702,7 @@ test_expect_success '--points-at finds annotated tags of tags' '
 
 test_expect_success 'recursive tagging should give advice' '
 	sed -e "s/|$//" <<-EOF >expect &&
-	hint: You have created a nested tag. The object referred to by your new is
+	hint: You have created a nested tag. The object referred to by your new tag is
 	hint: already a tag. If you meant to tag the object that it points to, use:
 	hint: |
 	hint: 	git tag -f nested annotated-v4.0^{}