SDL_ttf: fixed the custom harfbuzz config.h for unix case

SDL Commits
#1 
From 59967dea0a4ef55b9c466bca95976f60b2d556dc Mon Sep 17 00:00:00 2001
From: Ozkan Sezer <[EMAIL REDACTED]>
Date: Mon, 12 Jul 2021 01:22:50 +0300
Subject: [PATCH] fixed the custom harfbuzz config.h for unix case

---
 external/harfbuzz-2.8.0/config.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/external/harfbuzz-2.8.0/config.h b/external/harfbuzz-2.8.0/config.h
index b31f5c5..7481128 100644
--- a/external/harfbuzz-2.8.0/config.h
+++ b/external/harfbuzz-2.8.0/config.h
@@ -2,7 +2,7 @@
 #  include "config_sdl_win32.h"
 
 #elif defined(__APPLE__) || defined(__ANDROID__) || defined(__unix__)
-#  include "config_sdl_android.h"
+#  include "config_sdl_unix.h"
 
 #else
 #error generate a harfbuzz config for your platform