tdf#128230 Require password if the Unprotect button is visible

Regression from commit a2279bb2f5

Before that requiring password depended on the current text of
the Protect/Unprotect button, which was changed dynamically.

This commit changed that logic and introduced two buttons in the
new .ui file that are hidden/shown dynamically.

The password condition however was changed to check the visibility
of the new Protect button instead of the Unprotect button.

Change-Id: Ie24e1b2d45fa92a375a29b7bc71689f9b83ae9dc
Reviewed-on: https://gerrit.libreoffice.org/81283
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

sfx2/source/dialog/securitypage.cxx

@@ -331,7 +331,7 @@ IMPL_LINK_NOARG(SfxSecurityPage_Impl, RecordChangesCBToggleHdl, weld::ToggleButt
     }
 
     const bool bNeedPasssword = !m_bOrigPasswordIsConfirmed
-            && m_xProtectPB->get_visible();
+            && m_xUnProtectPB->get_visible(); // tdf#128230 Require password if the Unprotect button is visible
     if (!bAlreadyDone && bNeedPasssword)
     {
         OUString aPasswordText;