Fix improper cleanup of operational data in sal-netconf-connector's disconnect

Use put instead of merge to fully replace operational data on ever yupdate

Change-Id: I8ebf19a9bcfaba9cc56be6967999754265e44236
Signed-off-by: Maros Marsalek <mmarsale@cisco.com>
Merge "Fix improper cleanup of operational data in sal-netconf-connector's disconnect"