monitor: add python-cryptography egg

stack/monitor/buildout.cfg

@@ -9,6 +9,7 @@ extends =
   ../../component/logrotate/buildout.cfg
   ../../component/gzip/buildout.cfg
   ../../component/lxml-python/buildout.cfg
+  ../../component/python-cryptography/buildout.cfg
 
 parts =
   slapos-cookbook
@@ -38,6 +39,7 @@ on-update = true
 recipe = zc.recipe.egg
 eggs =
   ${lxml-python:egg}
+  ${python-cryptography:egg}
   plone.recipe.command
   collective.recipe.template
   cns.recipe.symlink