Ignore built git-lost+found.

Signed-off-by: Junio C Hamano <junkio@cox.net>

.gitignore

@@ -42,6 +42,7 @@ git-index-pack
 git-init-db
 git-local-fetch
 git-log
+git-lost+found
 git-ls-files
 git-ls-remote
 git-ls-tree