tdf#126686 Chart: fix crash

Regression from commit: fa0a981af41a2606541eec1cb20a379a739691e0
(tdf#114166 DOCX chart import: fix missing complex categories)

Change-Id: I164ed45280fcf7034fa3be82fd80efc4f03e5ed9
Reviewed-on: https://gerrit.libreoffice.org/76972
Reviewed-by: László Németh <nemeth@numbertext.org>
Tested-by: Jenkins
diff --git a/chart2/source/tools/InternalData.cxx b/chart2/source/tools/InternalData.cxx
index b7a5118..fcf3bf4 100644
--- a/chart2/source/tools/InternalData.cxx
+++ b/chart2/source/tools/InternalData.cxx
@@ -221,7 +221,7 @@ void InternalData::setComplexRowLabel( sal_Int32 nRowIndex, const vector< uno::A
        enlargeData( 0, nRowIndex+1 );
    }
    sal_Int32 nSize = static_cast<sal_Int32>( m_aRowLabels[nRowIndex].size() );
    if( nSize >= 1 )
    if( nSize >= 1 && !rComplexLabel.empty() )
    {
        m_aRowLabels[nRowIndex].resize(nSize+1);
        m_aRowLabels[nRowIndex][nSize] = rComplexLabel[0];