tdf#100222: Inform user that a restart is needed after toggling OpenCL use

Change-Id: Ic33cb02440276bc0601c86f2c9eab7d74a6b9874
diff --git a/cui/source/options/optopencl.cxx b/cui/source/options/optopencl.cxx
index 025cc39..776bb0f 100644
--- a/cui/source/options/optopencl.cxx
+++ b/cui/source/options/optopencl.cxx
@@ -167,6 +167,9 @@ bool SvxOpenCLTabPage::FillItemSet( SfxItemSet* )
    {
        maConfig.set();
        bModified = true;

        ScopedVclPtrInstance<MessageDialog> aWarnBox(this, CUI_RES(RID_SVXSTR_OPTIONS_RESTART), VclMessageType::Info);
        aWarnBox->Execute();
    }

    if (bModified)