[Lock Screen] Fix avatar not showing in software rendering

The circular avatar is a custom ShaderEffectItem and as such does not work with software rendering.
This is only used as a fallback for when the lock screen crashes because of e.g. graphics drivers anyway

Differential Revision: https://phabricator.kde.org/D14051

lookandfeel/contents/components/UserDelegate.qml

@@ -18,7 +18,7 @@
  *   51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  */
 
-import QtQuick 2.4
+import QtQuick 2.8
 
 import org.kde.plasma.core 2.0 as PlasmaCore
 import org.kde.plasma.components 2.0 as PlasmaComponents
@@ -48,6 +48,7 @@ Item {
 
     Item {
         id: imageSource
+        anchors.horizontalCenter: parent.horizontalCenter
         width: faceSize
         height: faceSize
 
@@ -81,7 +82,8 @@ Item {
 
         property var source: ShaderEffectSource {
             sourceItem: imageSource
-            hideSource: true
+            // software rendering is just a fallback so we can accept not having a rounded avatar here
+            hideSource: wrapper.GraphicsInfo.api !== GraphicsInfo.Software
             live: false
         }