git-fetch: Reset shallow_depth before auto-following tags.

Otherwise fetching the tags could also fetch commits up to the
specified depth, which isn't the expected behavior.

Signed-off-by: Alexandre Julliard <julliard@winehq.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

git-fetch.sh

@@ -461,6 +461,8 @@ case "$no_tags$tags" in
 	case "$taglist" in
 	'') ;;
 	?*)
+		# do not deepen a shallow tree when following tags
+		shallow_depth=
 		fetch_main "$taglist" ;;
 	esac
 esac