scripted-diff: Add copyright headers to QML files

-BEGIN VERIFY SCRIPT-
git ls-files ./src/qml/pages | xargs -I % ./contrib/devtools/copyright_header.py insert %
-END VERIFY SCRIPT-

Author: hebasto

src/qml/pages/initerrormessage.qml

@@ -1,3 +1,7 @@
+// Copyright (c) 2021 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
 import QtQuick 2.12
 import QtQuick.Dialogs 1.3
 

src/qml/pages/stub.qml

@@ -1,3 +1,7 @@
+// Copyright (c) 2021 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
 import QtQml 2.12
 import QtQuick.Controls 2.12