optimized error logging in convert_xml_to_marc21
optimized error logging in convert_xml_to_marc21

ubtue/ub_tools,ubtue/ub_tools,ubtue/ub_tools,ubtue/ub_tools,ubtue/ub_tools,ubtue/ub_tools,ubtue/ub_tools,ubtue/ub_tools