SDL: Revert "Add window title to app_ids for different"

From a71ac0eb0665075cf9c17ed2b71d0195f3a157d7 Mon Sep 17 00:00:00 2001
From: Sam Lantinga <[EMAIL REDACTED]>
Date: Wed, 7 Dec 2022 07:39:40 -0800
Subject: [PATCH] Revert "Add window title to app_ids for different"

This reverts commit 39eab4bf44472790dddf02490ac260f810c30c9a.

From @Kontrabant:
Making windows use the window title as the app ID by default doesn't seem like the right direction. The app ID is used by window managers to group windows from the same application together for switching between with alt-tilde and such functionality, and giving each window it's own app ID would break this.
---
 src/video/wayland/SDL_waylandwindow.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/src/video/wayland/SDL_waylandwindow.c b/src/video/wayland/SDL_waylandwindow.c
index 907224710212..b684489bd391 100644
--- a/src/video/wayland/SDL_waylandwindow.c
+++ b/src/video/wayland/SDL_waylandwindow.c
@@ -1270,11 +1270,7 @@ void Wayland_ShowWindow(_THIS, SDL_Window *window)
             }
         } else {
             data->shell_surface.xdg.roleobj.toplevel = xdg_surface_get_toplevel(data->shell_surface.xdg.surface);
-            if (c->classname != NULL) {
-                xdg_toplevel_set_app_id(data->shell_surface.xdg.roleobj.toplevel, c->classname);
-            } else {
-                xdg_toplevel_set_app_id(data->shell_surface.xdg.roleobj.toplevel, window->title);
-            }
+            xdg_toplevel_set_app_id(data->shell_surface.xdg.roleobj.toplevel, c->classname);
             xdg_toplevel_add_listener(data->shell_surface.xdg.roleobj.toplevel, &toplevel_listener_xdg, data);
         }
     }