Fix proper escaping in meta/sphinx.yml
diff --git a/sphinx/meta/sphinx.yml b/sphinx/meta/sphinx.yml
index 884533d..311bd3e 100644
--- a/sphinx/meta/sphinx.yml
+++ b/sphinx/meta/sphinx.yml
@@ -8,4 +8,4 @@
       name: server
       param:
         version:
-          value: {{ salt['cmd.run']('sphinx-build --version')|replace('Sphinx (sphinx-build) ', '') }}
+          value: "{{ salt['cmd.run']('sphinx-build --version 2>/dev/null || echo unknown')|replace('Sphinx (sphinx-build) ', '') }}"