off-by-one error: columns are numbered from one, but the array from 0

Change-Id: I14ef451999fa1f9d57757a9e231fc66be4e53f3a
Reviewed-on: https://gerrit.libreoffice.org/23406
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>
diff --git a/dbaccess/source/core/api/KeySet.cxx b/dbaccess/source/core/api/KeySet.cxx
index 6b2400e..58be2f2 100644
--- a/dbaccess/source/core/api/KeySet.cxx
+++ b/dbaccess/source/core/api/KeySet.cxx
@@ -944,7 +944,7 @@ void OKeySet::copyRowValue(const ORowSetRow& _rInsertRow,ORowSetRow& _rKeyRow,sa
    for(sal_Int32 i = 1;aParaIter != aParaEnd;++aParaIter,++aParaValuesIter,++i)
    {
        ORowSetValue aValue(*aParaValuesIter);
        aValue.setSigned(m_aSignedFlags[aParaIter->second.nPosition]);
        aValue.setSigned(m_aSignedFlags[aParaIter->second.nPosition-1]);
        if ( (_rInsertRow->get())[aParaIter->second.nPosition] != aValue )
        {
            ORowSetValueVector aCopy(m_aParameterValueForCache);