[Notifications] Fix speed overlapping units

There's 4 unit (Items got added) now. Unlikely a job has all of them, however.

applets/notifications/package/contents/ui/JobDetails.qml

@@ -140,7 +140,7 @@ GridLayout {
 
     PlasmaExtras.DescriptiveLabel {
         Layout.column: 1
-        Layout.row: 2 + 3
+        Layout.row: 2 + 4
         Layout.fillWidth: true
         text: jobDetails.speed > 0 ? i18ndc("plasma_applet_org.kde.plasma.notifications", "Bytes per second", "%1/s",
                                            KCoreAddons.Format.formatByteSize(jobDetails.speed)) : ""