Update redis_cache.py

fix comment position

gluon/contrib/redis_cache.py

@@ -159,8 +159,8 @@ class RedisClient(object):
                     lock_key = '%s:__lock' % newKey
                     randomvalue = time.time()
                     al = acquire_lock(self.r_server, lock_key, randomvalue)
-                    # someone may have computed it
                     try:
+                        # someone may have computed it
                         obj = self.r_server.get(newKey)
                         if obj is None:
                             value = self.cache_it(newKey, f, time_expire)