Update SDL to version 2.0.14.

libs/SDL2/test/testrumble.c

@@ -1,5 +1,5 @@
 /*
-  Copyright (C) 1997-2019 Sam Lantinga <slouken@libsdl.org>
+  Copyright (C) 1997-2020 Sam Lantinga <slouken@libsdl.org>
 
   This software is provided 'as-is', without any express or implied
   warranty.  In no event will the authors be held liable for any damages
@@ -147,7 +147,7 @@ int
 main(int argc, char *argv[])
 {
     SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "SDL compiled without Haptic support.\n");
-    exit(1);
+    return 1;
 }
 
 #endif