[xs][middleware] Bug fix: check that lang list is not empty (old cook…

…ie setup will give a server 500 error)

ckan/config/middleware.py

@@ -139,9 +139,9 @@ def get_cookie_lang(self, environ):
         if cookie:
             cookies = [c.strip() for c in cookie.split(';')]
             lang = [c.split('=')[1] for c in cookies \
-                    if c.startswith('ckan_lang')][0]
-            if lang in self.local_list:
-                return lang
+                    if c.startswith('ckan_lang')]
+            if lang and lang[0] in self.local_list:
+                return lang[0]
         return None
 
     def __call__(self, environ, start_response):