Deleting mountpoints when netconf-topology is under stress seems not to work properly

Topology Owner Ha suite tries to repeatedly configure and deconfigure multiple netconf mounpoints. After that suite reboots topology owner and expects maximum number of configured netconf mountpoints. This ends in following error:
https://logs.opendaylight.org/releng/jenkins092/netconf-csit-3node-cluster-stress-all-nitrogen/46/log.html.gz#s1-s2-t7

There can be some issue with deleting ountpoints when netconf topology is under stress, but we should also check the correctness of the suite, because now I am not sure how it exactly works.