fix: add missing cvar register for ag_hl25_mp5_spread

Author: 7mochi

src/game/server/agglobal.cpp

@@ -702,6 +702,7 @@ void AgInitGame()
 	CVAR_REGISTER(&ag_hl25_satchel_controls);
 	CVAR_REGISTER(&ag_hl25_handgrenade_throw);
 	CVAR_REGISTER(&ag_hl25_mp5_max_initial_ammo);
+	CVAR_REGISTER(&ag_hl25_mp5_spread);
 
 	Command.Init();