Fix QtQuick.Controls version in addressbook example

examples/addressbook/qml/PhoneInput.qml

@@ -25,7 +25,7 @@
 
 import QtQuick 2.9
 import QtQuick.Layouts 1.2
-import QtQuick.Controls 2.3
+import QtQuick.Controls 2.4
 
 InputRow {
     property alias number: _inputItem.text

examples/addressbook/qml/StackItem.qml

@@ -24,7 +24,7 @@
  */
 
 import QtQuick 2.0
-import QtQuick.Controls 2.9
+import QtQuick.Controls 2.4
 
 Item {
     property StackView stack: null

examples/addressbook/qml/main.qml

@@ -24,7 +24,7 @@
  */
 
 import QtQuick 2.9
-import QtQuick.Controls 2.9
+import QtQuick.Controls 2.4
 
 import qtprotobuf.examples 1.0
 import examples.addressbook 1.0