Fixes offlining an instance not changing the config

TGServerService/ServerInstance/ServerInstance.cs

@@ -126,6 +126,13 @@ namespace TGServerService
 			return Config.Directory;
 		}
 
+		/// <summary>
+		/// Sets <see cref="InstanceConfig.Enabled"/> of <see cref="Config"/> to <see langword="false"/>
+		/// </summary>
+		public void Offline()
+		{
+			Config.Enabled = false;
+		}
 
 		//mostly generated code with a call to RunDisposals()
 		//you don't need to open this

TGServerService/Service.cs

@@ -593,6 +593,7 @@ namespace TGServerService
 							if (ic.Name == Name)
 							{
 								path = ic.Directory;
+								ic.Enabled = true;
 								return SetupOneInstance(ic);
 							}
 						}
@@ -612,6 +613,7 @@ namespace TGServerService
 					var inst = (ServerInstance)host.SingletonInstance;
 					host.Close();
 					path = inst.ServerDirectory();
+					inst.Offline();
 					inst.Dispose();
 					return null;
 				}