SDL_ttf: automake >= 1.16 is required because of subdir-objects.

SDL Commits
1 
From 215074bbe7a826fb2d7aff0d702dea4c8908e3c3 Mon Sep 17 00:00:00 2001
From: Ozkan Sezer <[EMAIL REDACTED]>
Date: Fri, 16 Apr 2021 14:05:24 +0300
Subject: [PATCH] automake >= 1.16 is required because of subdir-objects.

---
 configure.ac | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac
index 541fa50..976b9e9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -44,7 +44,7 @@ dnl Detect the canonical build and host environments
 AC_CANONICAL_HOST
 
 dnl Setup for automake
-AM_INIT_AUTOMAKE([foreign subdir-objects tar-ustar])
+AM_INIT_AUTOMAKE([1.16 foreign subdir-objects tar-ustar])
 
 dnl Check for tools
 AC_PROG_CC