mining: optimize update function, improve performance

pages/Transfer.qml

@@ -694,8 +694,6 @@ Rectangle {
                 // Light wallet is always ready
                 pageRoot.enabled = true;
                 root.warningContent = "";
-                // check if daemon was already mining and add mining logo if true
-                middlePanel.miningView.update();
             }
         }
     }