fix multimonitor corners

Lock.qml

@@ -23,7 +23,12 @@ WlSessionLock {
             id: content
             anchors.fill: parent
             opacity: !lock.animate || capture.ready
-            color: "#141414"
+            color: "#000"
+            Rectangle {
+                anchors.fill: parent
+                radius: 16
+                color: "#141414"
+            }
             Rectangle {
                 anchors {
                     bottom: parent.bottom
@@ -80,7 +85,7 @@ WlSessionLock {
             anchors.fill: parent
             color: "white"
             opacity: capture.ready
-            radius: 0
+            radius: 12
             RectangularShadow {
                 anchors.fill: parent
                 spread: 2
@@ -144,7 +149,7 @@ WlSessionLock {
             }
             NumberAnimation on radius {
                 running: exit.running
-                to: 0
+                to: 12
                 duration: 800
             }
         }