Fix fdo#44040 VIEWING: Crash when page preview after <f4> (data sources)

Caolán fixed Iterator management which was buggy. (thank you !)
diff --git a/dbaccess/source/ui/browser/unodatbr.cxx b/dbaccess/source/ui/browser/unodatbr.cxx
index 4d980a0..6e31141 100644
--- a/dbaccess/source/ui/browser/unodatbr.cxx
+++ b/dbaccess/source/ui/browser/unodatbr.cxx
@@ -1410,24 +1410,22 @@ void SAL_CALL SbaTableQueryBrowser::disposing( const EventObject& _rSource ) thr
        Reference< XDispatch > xSource(_rSource.Source, UNO_QUERY);
        if(xSource.is())
        {
            for (  ExternalFeaturesMap::iterator aLoop = m_aExternalFeatures.begin();
                  aLoop != m_aExternalFeatures.end();
                  ++aLoop
                )
            ExternalFeaturesMap::iterator aLoop = m_aExternalFeatures.begin();
            ExternalFeaturesMap::iterator aEnd = m_aExternalFeatures.end();
            while (aLoop != aEnd)
            {
                if ( aLoop->second.xDispatcher.get() == xSource.get() )
                ExternalFeaturesMap::iterator aI = aLoop++;
                if ( aI->second.xDispatcher.get() == xSource.get() )
                {
                    ExternalFeaturesMap::iterator aPrevious = aLoop;
                    --aPrevious;
                    sal_uInt16 nSlot = aI->first;

                    // remove it
                    m_aExternalFeatures.erase( aLoop );
                    m_aExternalFeatures.erase(aI);

                    // maybe update the UI
                    implCheckExternalSlot(aLoop->first);
                    implCheckExternalSlot(nSlot);

                    // continue, the same XDispatch may be resposible for more than one URL
                    aLoop = aPrevious;
                }
            }
        }