qml: Remove duplicate property in BlockClock

Author: johnny9

src/qml/components/BlockClock.qml

@@ -24,7 +24,6 @@ Item {
     property alias header: mainText.text
     property alias headerSize: mainText.font.pixelSize
     property alias subText: subText.text
-    property int headerSize: 32
     property bool connected: nodeModel.numOutboundPeers > 0
     property bool synced: nodeModel.verificationProgress > 0.999
     property string syncProgress: formatProgressPercentage(nodeModel.verificationProgress * 100)