Declare hoverEnabled: true explicitly in CustomButton

Signed-off-by: Claudio Cambra <claudio.cambra@nextcloud.com>

src/gui/tray/CustomButton.qml

@@ -45,6 +45,8 @@ Button {
     rightPadding: root.text === "" ? Style.smallSpacing : Style.standardSpacing
     implicitWidth: contentItem.implicitWidth + leftPadding + rightPadding
 
+    hoverEnabled: true
+
     NCToolTip {
         text: root.toolTipText
         visible: root.toolTipText !== "" && root.hovered