fix bug in SwWrtShell::Insert

ever since
    commit 9ce55608
    Date:   Tue May 18 13:13:46 2004 +0000
    INTEGRATION: CWS swundo01 (1.22.126); FILE MERGED

found by my unusedvariablesmore plugin

Change-Id: I6cc1e7959cabf6452a37829482600f38a90cd993
Reviewed-on: https://gerrit.libreoffice.org/52447Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

sw/source/uibase/wrtsh/wrtsh1.cxx

@@ -214,7 +214,7 @@ void SwWrtShell::Insert( const OUString &rStr )
             aTmpStr += rStr;
             aTmpStr += SwResId(STR_END_QUOTE);
 
-            aRewriter.AddRule(UndoArg3, rStr);
+            aRewriter.AddRule(UndoArg3, aTmpStr);
         }
 
         StartUndo(SwUndoId::REPLACE, &aRewriter);