Fixed blurSetting

CURA-2835

cura/Settings/MachineManager.py

@@ -248,7 +248,6 @@ class MachineManager(QObject):
 
     def _onActiveExtruderStackChanged(self):
         self.blurSettings.emit()  # Ensure no-one has focus.
-
         old_active_container_stack = self._active_container_stack
 
         if self._active_container_stack and self._active_container_stack != self._global_container_stack:

resources/qml/Cura.qml

@@ -539,7 +539,7 @@ UM.MainWindow
         target: Cura.MachineManager
         onBlurSettings:
         {
-            contentItem.focus = true
+            forceActiveFocus()
         }
     }