windows/gles: do not unload EGL when context is destroyed

It's legitimate to have multiple contexts.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
(cherry picked from commit 93861e1de0)

src/video/windows/SDL_windowsopengles.c

@@ -93,7 +93,6 @@ WIN_GLES_CreateContext(_THIS, SDL_Window *window)
 void WIN_GLES_DeleteContext(_THIS, SDL_GLContext context)
 {
     SDL_EGL_DeleteContext(_this, context);
-    WIN_GLES_UnloadLibrary(_this);
 }
 
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