SDL: X11: fix removing SDL_WINDOW_HIDDEN flags (thanks @zturtleman)

SDL Commits
1 
From 71eb78e7900c1c3b4a80b1d5b43d748700cf18b7 Mon Sep 17 00:00:00 2001
From: Sylvain <[EMAIL REDACTED]>
Date: Wed, 28 Dec 2022 23:18:00 +0100
Subject: [PATCH] X11: fix removing SDL_WINDOW_HIDDEN flags (thanks
 @zturtleman)

---
 src/video/x11/SDL_x11window.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/video/x11/SDL_x11window.c b/src/video/x11/SDL_x11window.c
index dc1dbb82a91c..1a65df8b7aba 100644
--- a/src/video/x11/SDL_x11window.c
+++ b/src/video/x11/SDL_x11window.c
@@ -306,7 +306,7 @@ static int SetupWindowData(_THIS, SDL_Window *window, Window w, BOOL created)
         window->w = attrib.width;
         window->h = attrib.height;
         if (attrib.map_state != IsUnmapped) {
-            window->flags &= SDL_WINDOW_HIDDEN;
+            window->flags &= ~SDL_WINDOW_HIDDEN;
         } else {
             window->flags |= SDL_WINDOW_HIDDEN;
         }