Fix bug 1514

Pin version of paramiko to 2.7.2

Change-Id: Ie9f7aaf10e78d5e243b75fc4523820473c19f4f9
Signed-off-by: David Garcia <david.garcia@canonical.com>
diff --git a/docker/RO/Dockerfile b/docker/RO/Dockerfile
index 25907b7..d91c533 100644
--- a/docker/RO/Dockerfile
+++ b/docker/RO/Dockerfile
@@ -49,6 +49,7 @@
 
 # ensure right version is installed as pyhton3-ccryptography install an old version
 RUN python3 -m pip install --upgrade "cryptography>=2.5"
+RUN python3 -m pip install --upgrade "paramiko==2.7.2"
 
 VOLUME /var/log/osm