fix config.json bug on windows (#544)

paddlehub/common/hub_server.py

@@ -46,7 +46,8 @@ class HubServer(object):
             config_file_path = os.path.join(CONF_HOME, 'config.json')
         if not os.path.exists(CONF_HOME):
             utils.mkdir(CONF_HOME)
-        if not os.path.exists(config_file_path):
+        if not os.path.exists(config_file_path) or 0 == os.path.getsize(
+                config_file_path):
             with open(config_file_path, 'w+') as fp:
                 lock.flock(fp, lock.LOCK_EX)
                 fp.write(json.dumps(default_server_config))

paddlehub/common/logger.py

@@ -62,7 +62,8 @@ class Logger(object):
         self.logger.setLevel(logging.DEBUG)
         self.logger.propagate = False
 
-        if os.path.exists(os.path.join(CONF_HOME, "config.json")):
+        config_path = os.path.join(CONF_HOME, "config.json")
+        if os.path.exists(config_path) and 0 < os.path.getsize(config_path):
             with open(os.path.join(CONF_HOME, "config.json"), "r") as fp:
                 level = json.load(fp).get("log_level", "DEBUG")
                 self.logLevel = level