[FEED PARSER] [NTB NITF] fixed by xpath in mapping
[FEED PARSER] [NTB NITF] fixed by xpath in mapping

xpath expression for metadata was bad, resulting in tests failing.

SDNTB-432

petrjasek/superdesk-ntb,petrjasek/superdesk-ntb,superdesk/superdesk-ntb,ioanpocol/superdesk-ntb,petrjasek/superdesk-ntb,superdesk/superdesk-ntb,ioanpocol/superdesk-ntb,ioanpocol/superdesk-ntb,petrjasek/superdesk-ntb,superdesk/superdesk-ntb,superdesk/superdesk-ntb