Move object disposal

Author: pglombardo

Source/HiveMQtt/Client/Connection/ConnectionManager.cs

@@ -197,6 +197,10 @@ internal async Task CancelBackgroundTasksAsync()
     /// </summary>
     public void Dispose()
     {
+        // Dispose managed resources.
+        this.cancellationTokenSource.Cancel();
+        this.cancellationTokenSource.Dispose();
+
         this.Dispose();
         /*
           This object will be cleaned up by the Dispose method.

Source/HiveMQtt/Client/HiveMQClientUtil.cs

@@ -173,11 +173,7 @@ protected virtual void Dispose(bool disposing)
                     Logger.Trace("HiveMQClient Dispose: Disconnecting connected client.");
                     _ = Task.Run(async () => await this.DisconnectAsync().ConfigureAwait(false));
                 }
-
-                // Dispose managed resources.
-                // this.cancellationTokenSource.Cancel();
-                // this.cancellationTokenSource.Dispose();
-            }
+             }
 
             // Call the appropriate methods to clean up
             // unmanaged resources here.