balance details: use onClicked event. Early return if balance is not available

electrum/gui/qml/components/controls/BalanceSummary.qml

@@ -146,7 +146,8 @@ Item {
 
     MouseArea {
         anchors.fill: parent
-        onPressAndHold: {
+        onClicked: {
+            if(Daemon.currentWallet.synchronizing || Network.server_status != 'connected') return
             app.stack.push(Qt.resolvedUrl('../BalanceDetails.qml'))
         }
     }