tdf#124586 sw_redlinehide: fix crash in SwTextNode::NumRuleChgd()

(regression from c180c9447256588fe5e7991e06642883574760ae)

Change-Id: Ie3c935ee5dd42187ca8ad2b28406b80e63c0d1e3
Reviewed-on: https://gerrit.libreoffice.org/70467
Reviewed-by: Michael Stahl <Michael.Stahl@cib.de>
Tested-by: Michael Stahl <Michael.Stahl@cib.de>
diff --git a/sw/source/core/txtnode/ndtxt.cxx b/sw/source/core/txtnode/ndtxt.cxx
index 6bf96c6..05135a9 100644
--- a/sw/source/core/txtnode/ndtxt.cxx
+++ b/sw/source/core/txtnode/ndtxt.cxx
@@ -2863,7 +2863,10 @@
        if ( pNumRule && pNumRule != GetNum()->GetNumRule() )
        {
            mpNodeNum->ChangeNumRule( *pNumRule );
            mpNodeNumRLHidden->ChangeNumRule( *pNumRule );
            if (mpNodeNumRLHidden)
            {
                mpNodeNumRLHidden->ChangeNumRule(*pNumRule);
            }
        }
    }