BUG-832 Fix exception from sal-netconf-connector.

Exception:
Ommiting from BA transaction: /(urn:opendaylight:inventory?revision=2013-08-19)nodes/(urn:opendaylight:inventory?revision=2013-08-19)node[{(urn:opendaylight:inventory?revision=2013-08-19)id=ios-xr-105}].

Fixed by treating capabilities from remote device as String instead of QName

Change-Id: I5cb59e111433ca60703bcf9a78d5b4578fc3b956
Signed-off-by: Maros Marsalek <mmarsale@cisco.com>
Merge "BUG-832 Fix exception from sal-netconf-connector."