Fixes
```
======================================================================
ERROR: setUpClass (ssh_test.BannerTest)
----------------------------------------------------------------------
Traceback (most recent call last):
File "/home/vsts/work/1/s/tests/testlib.py", line 625, in setUpClass
cls.dockerized_ssh = DockerizedSshDaemon(**daemon_args)
File "/home/vsts/work/1/s/tests/testlib.py", line 553, in __init__
self.start_container()
File "/home/vsts/work/1/s/tests/testlib.py", line 533, in start_container
self._get_container_port()
File "/home/vsts/work/1/s/tests/testlib.py", line 510, in _get_container_port
self.port = int(bport)
ValueError: invalid literal for int() with base 10: ':]:32770'
```
6258365df6
