Added DisconnectButton_Patch

- Prevent host from clicking "Disconnect" in the main menu if peers are still connected.

Fika.Core/FikaPlugin.cs

@@ -213,6 +213,7 @@ protected void Awake()
             new BotCacher_Patch().Enable();
             new InventoryScroll_Patch().Enable();
             new AbstractGame_InRaid_Patch().Enable();
+            new DisconnectButton_Patch().Enable();
 #if GOLDMASTER
             new TOS_Patch().Enable();
 #endif

Fika.Core/UI/Patches/DisconnectButton_Patch.cs

@@ -0,0 +1,32 @@
+using Comfort.Common;
+using EFT.UI;
+using Fika.Core.Coop.Matchmaker;
+using Fika.Core.Networking;
+using SPT.Reflection.Patching;
+using System.Reflection;
+
+namespace Fika.Core.UI.Patches
+{
+    public class DisconnectButton_Patch : ModulePatch
+    {
+        protected override MethodBase GetTargetMethod()
+        {
+            return typeof(MenuScreen).GetMethod(nameof(MenuScreen.method_11));
+        }
+
+        [PatchPrefix]
+        static bool Prefix()
+        {
+            if (MatchmakerAcceptPatches.IsServer)
+            {
+                FikaServer server = Singleton<FikaServer>.Instance;
+                if (server != null && server.NetServer.ConnectedPeersCount > 0)
+                {
+                    NotificationManagerClass.DisplayWarningNotification($"You cannot disconnect while there are still peers connected! Remaining: {server.NetServer.ConnectedPeersCount}");
+                    return false;
+                }
+            }
+            return true;
+        }
+    }
+}