allow text as dates in inline array of holidays for NETWORKDAYS()

Change-Id: I0c5438a0ee23a5974495a9f782b3f22ef7472c87
diff --git a/sc/source/core/tool/interpr2.cxx b/sc/source/core/tool/interpr2.cxx
index ed467e3..df32da3 100644
--- a/sc/source/core/tool/interpr2.cxx
+++ b/sc/source/core/tool/interpr2.cxx
@@ -346,7 +346,7 @@

    if ( nParamCount >= 3 )
    {
        GetSortArray( 1, rSortArray, nullptr, false, true );
        GetSortArray( 1, rSortArray, nullptr, true, true );
        size_t nMax = rSortArray.size();
        for ( size_t i = 0; i < nMax; i++ )
            rSortArray.at( i ) = ::rtl::math::approxFloor( rSortArray.at( i ) ) + nNullDate;