tdf#124815 CRASH: inserting a column

regression from
    commit 7282014e362a1529a36c88eb308df8ed359c2cfa
    Date:   Fri Feb 1 15:15:16 2019 +0100
    tdf#50916 Makes numbers of columns dynamic.

Change-Id: If82689218344d1fea025d7d6e409dd5ec9e2d3b3
Reviewed-on: https://gerrit.libreoffice.org/70924
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>
diff --git a/sc/source/core/data/table2.cxx b/sc/source/core/data/table2.cxx
index fa35ef2..218ca0c 100644
--- a/sc/source/core/data/table2.cxx
+++ b/sc/source/core/data/table2.cxx
@@ -1501,7 +1501,7 @@
    if (!ValidCol(nCol))
        return false;

    return aCol[nCol].SetFormulaCells(nRow, rCells);
    return CreateColumnIfNotExists(nCol).SetFormulaCells(nRow, rCells);
}

svl::SharedString ScTable::GetSharedString( SCCOL nCol, SCROW nRow ) const