substitution vars: replace appname_ with env_

wcs/qommon/http_request.py

@@ -63,11 +63,10 @@ class HTTPRequest(quixote.http_request.HTTPRequest):
                 self.form[k] = v.encode(site_charset)
 
     def get_substitution_variables(self):
-        # env variables starting with "APPNAME_" are exported to
-        # substitutions variables
+        # environment variables APPNAME_* are exported to env_*
         prefix = get_publisher().APP_NAME.lower() + '_'
-        vars = {}
+        variables = {}
         for k, v in self.environ.items():
             if k.lower().startswith(prefix):
-                vars['env_' + k.lower()] = v
-        return vars
+                variables['env_' + k.lower()[len(prefix):]] = v
+        return variables