use ScMarkData::GetMarkedRangesForTab(nTab) in SingleColumnSpanSet::scan()

That always worked only by chance only on the first selected sheet, luckily
with ScMarkData it seems to be used only in ScColumn::GetOptimalColWidth()
which usually operates on the visible sheet.

So now setting optimal column width actually works on all selected sheets for
the selected columns.

Change-Id: I5944b943824a67d77b549b6cdfc0b2550b8d77b8

sc/source/core/data/columnspanset.cxx

@@ -329,7 +329,7 @@ void SingleColumnSpanSet::scan(const ScMarkData& rMark, SCTAB nTab, SCCOL nCol)
         // This table is not selected. Nothing to scan.
         return;
 
-    ScRangeList aRanges = rMark.GetMarkedRanges();
+    ScRangeList aRanges = rMark.GetMarkedRangesForTab(nTab);
     scan(aRanges, nTab, nCol);
 }