update SDL soruce to 2.0.14

Edward Rudd

2021-06-15 dec7875a6e23212021e4d9080330a42832dfe02a

 source/test/testmessage.c

@@ -106,6 +106,24 @@
        quit(1);
    }

    success = SDL_ShowSimpleMessageBox(SDL_MESSAGEBOX_ERROR,
                NULL,
                "NULL Title",
                NULL);
    if (success == -1) {
        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Error Presenting MessageBox: %s\n", SDL_GetError());
        quit(1);
    }

    success = SDL_ShowSimpleMessageBox(SDL_MESSAGEBOX_ERROR,
                "NULL Message",
                NULL,
                NULL);
    if (success == -1) {
        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Error Presenting MessageBox: %s\n", SDL_GetError());
        quit(1);
    }

    /* Google says this is Traditional Chinese for "beef with broccoli" */
    success = SDL_ShowSimpleMessageBox(SDL_MESSAGEBOX_ERROR,
                "UTF-8 Simple MessageBox",