Revert "dep/msvc: Update SDL2 to 2.0.14"

This reverts commit 8debaa34d9.

Seems to be a few regressions, namely XBox Controller Rumble, other
controllers not detecting, etc.

dep/msvc/sdl2/include/SDL_egl.h

@@ -1,6 +1,6 @@
 /*
   Simple DirectMedia Layer
-  Copyright (C) 1997-2020 Sam Lantinga <slouken@libsdl.org>
+  Copyright (C) 1997-2019 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
@@ -390,9 +390,6 @@ typedef enum {
 #ifndef WIN32_LEAN_AND_MEAN
 #define WIN32_LEAN_AND_MEAN 1
 #endif
-#ifndef NOMINMAX   /* don't define min() and max(). */
-#define NOMINMAX
-#endif
 #include <windows.h>
 
 #if __WINRT__