Handle undefined variable

Signed-off-by: Aurélien Bompard <aurelien@bompard.org>

roles/openshift-apps/noggin/templates/deploymentconfig.yml

@@ -69,7 +69,7 @@ spec:
           value: "deploy.wsgi"
         - name: APP_CONFIG
           value: "/etc/noggin/gunicorn.conf.py"
-        {% if subdir %}
+        {% if subdir is defined %}
         - name: SCRIPT_NAME
           value: "{{ subdir }}"
         {% endif %}

roles/openshift-apps/noggin/templates/noggin.cfg.py

@@ -7,7 +7,7 @@ def from_file(path):
     return open(path, 'r').read().strip()
 
 
-{% if subdir %}
+{% if subdir is defined %}
 # Deployed to a subpath
 APPLICATION_ROOT = '{{ subdir }}/'
 {% endif %}