Fix IDE0251

OpenRA.Game/Network/OrderManager.cs

@@ -70,7 +70,7 @@ namespace OpenRA.Network
 			public int Client;
 			public Order Order;
 
-			public override string ToString()
+			public override readonly string ToString()
 			{
 				return $"ClientId: {Client} {Order}";
 			}

OpenRA.Game/Network/SyncReport.cs

@@ -300,7 +300,7 @@ namespace OpenRA.Network
 
 			public object this[int index]
 			{
-				get
+				readonly get
 				{
 					if (item2OrSentinel == Sentinel)
 						return ((object[])item1OrArray)[index];