Fix Exception reported: Invalid convar handle

[cH1yoi]

L 11/13/2024 - 00:53:35: [SM] Exception reported: Invalid convar handle 41400405 (error 3)
L 11/13/2024 - 00:53:35: [SM] Blaming: match_vote.smx
L 11/13/2024 - 00:53:35: [SM] Call stack trace:
L 11/13/2024 - 00:53:35: [SM] [0] ConVar.SetInt
L 11/13/2024 - 00:53:35: [SM] [1] Line 102, x:\GitHub\L4D2-Competitive-Rework\addons\sourcemod\scripting\match_vote.sp::OnPluginEnd

This occurred because the plugin was trying to access ConVar handles that had already been cleaned up by SourceMod during the unload process.

Solution

• Added ConVar handle validity checks in Listener_Quit to reset sv_maxplayers before server shutdown
• Improved handle management to prevent accessing invalid handles during plugin unload
• Added safety checks to prevent potential null pointer access

Technical Details

• Moved the primary sv_maxplayers reset logic to Listener_Quit which triggers before server shutdown
• Added null checks for ConVar handles before attempting to modify their values
• Used g_bShutdown flag to track proper shutdown sequence

While this error was mostly cosmetic and didn't affect core functionality, this fix provides a cleaner shutdown process and eliminates error messages in server logs.

[cH1yoi]

There are still some minor issues