Configuring new netconf mounpoints when netconf-topology is under stress seems not to work properly

Netconf scale test tries to configure lot of netconf mountpoints and then perform various tasks on them.

However, test is not able to configure all of the desired mountpoints and this end with following error:
https://logs.opendaylight.org/releng/jenkins092/netconf-csit-1node-periodic-scale-only-nitrogen/115/log.html.gz#s1-s4-t2-k3-k4-k479