fix bug: fail to init in offline enviroment

paddlehub/common/hub_server.py

@@ -221,11 +221,14 @@ class HubServer(object):
                 raise
             else:
                 pass
-        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:
+        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