GSOD: Ungrab server before opening new connection

Going here while having grabbed the server would cause a deadlock when
opening the new connection.

src/alert.c

@@ -1,6 +1,6 @@
 /*
  * Copyright (C) 2000-2007 Carsten Haitzler, Geoff Harrison and various contributors
- * Copyright (C) 2004-2022 Kim Woelders
+ * Copyright (C) 2004-2023 Kim Woelders
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to
@@ -38,6 +38,8 @@
 #include <X11/extensions/Xcomposite.h>
 #endif
 
+void                EUngrabServer(void);
+
 #define ExTextExtents XmbTextExtents
 #define ExDrawString XmbDrawString
 
@@ -188,6 +190,8 @@ ShowAlert(const char *title,
    SoundPlay(SOUND_ALERT);
 #endif
 
+   EUngrabServer();
+
    if (!fmt)
       return;