remove cryptography pip module

Change-Id: I2438e1c8c32de43e3fabeb10709016ba9190caf2
diff --git a/containers/xos/Dockerfile.base b/containers/xos/Dockerfile.base
index 6c73f6a..9ad5b71 100644
--- a/containers/xos/Dockerfile.base
+++ b/containers/xos/Dockerfile.base
@@ -71,6 +71,9 @@
     requests \
     urllib3
 
+# uninstall cryptography
+RUN /usr/bin/yes | pip uninstall cryptography
+
 # Required for Ansible 2.x OpenStack os_* modules
 RUN pip install --upgrade pbr && \
     pip install --upgrade six && \