fix bug: fail to init in offline enviroment

paddlehub/common/hub_server.py

@@ -221,12 +221,15 @@ class HubServer(object):
                 raise
             else:
                 pass
+        try:
             file_url = self.config[
                 'resource_storage_server_url'] + RESOURCE_LIST_FILE
             result, tips, self.resource_list_file = default_downloader.download_file(
                 file_url, save_path=hub.CACHE_HOME, replace=True)
             if not result:
                 return False
+        except:
+            return False
         return True