Rework client to be non static

MistoxServer/Server/ServerConnection.cs

@@ -69,7 +69,7 @@ namespace Mistox.Server {
 
                     }
                 } catch (Exception e) {
-                    ClientInterface.ServerClientInstance.Alive = false;
+                    _parent.Alive = false;
                     Dispose();
                     Console.WriteLine("TCP Receive exception: " + e.Message);
                 }