Update ft_printf for its .gitignore

diff --git a/ft_printf b/ft_printf
index 7f5ddfc2e05cf67a9aa52e77fb6fab96439b0d65..21c446f15c1c1e65d3fe339933b869e930bd25a5 160000 (submodule)
--- a/ft_printf
+++ b/ft_printf
@@ -1 +1 @@
-Subproject commit 7f5ddfc2e05cf67a9aa52e77fb6fab96439b0d65
+Subproject commit 21c446f15c1c1e65d3fe339933b869e930bd25a5