fdo#56776: Change in formula options should cause repaint.

Else Calc would fail to update the column headers due to A1 to R1C1
change (and vise versa).

Change-Id: I2c403212f5bc539aea92370e60da96f480549d6d

sc/source/ui/app/scmod.cxx

@@ -1068,6 +1068,11 @@ void ScModule::ModifyOptions( const SfxItemSet& rOptSet )
     if (rOptSet.HasItem(SID_SCFORMULAOPTIONS, &pItem))
     {
         const ScFormulaOptions& rOpt = ((const ScTpFormulaItem*)pItem)->GetFormulaOptions();
+
+        if (!pFormulaCfg || (*pFormulaCfg != rOpt))
+            // Formula options have changed. Repaint the column headers.
+            bRepaint = true;
+
         SetFormulaOptions( rOpt );
 
         if ( pDocSh )