Resolves: tdf#161133 read-only widget should have deactivated calendar

a problem since:

commit 6e7e19d9c300dbdd279789b09f94781e946fad52
Date:   Wed Jul 15 12:10:32 2020 +0100

    weld DateControl

Change-Id: I367c4237903655ad02c0c4af70ae0383b8a89f25
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/167802
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolan.mcnamara@collabora.com>
diff --git a/include/svtools/editbrowsebox.hxx b/include/svtools/editbrowsebox.hxx
index 9dcc644..8acd3fd 100644
--- a/include/svtools/editbrowsebox.hxx
+++ b/include/svtools/editbrowsebox.hxx
@@ -829,6 +829,8 @@ namespace svt

        void SetDate(const Date& rDate);

        virtual void SetEditableReadOnly(bool bReadOnly) override;

        virtual void dispose() override;
    private:
        std::unique_ptr<weld::MenuButton> m_xMenuButton;
diff --git a/svtools/source/brwbox/ebbcontrols.cxx b/svtools/source/brwbox/ebbcontrols.cxx
index 06500b4..71fc13d 100644
--- a/svtools/source/brwbox/ebbcontrols.cxx
+++ b/svtools/source/brwbox/ebbcontrols.cxx
@@ -586,6 +586,12 @@ namespace svt
        m_xCalendar->set_date(rDate);
    }

    void DateControl::SetEditableReadOnly(bool bReadOnly)
    {
        FormattedControlBase::SetEditableReadOnly(bReadOnly);
        m_xMenuButton->set_sensitive(!bReadOnly);
    }

    void DateControl::dispose()
    {
        m_xTodayBtn.reset();