Python EmrResponseError:505 HTTP版本不受支持

当我从ec2机器上运行python文件时，出现了以下错误

Hadoop版本：2.4.0 ami版本：3.5.0 Boto版本：2.32.0

Traceback (most recent call last):
  File "/home/ec2-user/logprocess/test_logs.py", line 182, in <module>
    job_id = emr_conn.run_jobflow(name=job_name,log_uri="s3://test.media.com/logs",hadoop_version='2.4.0',master_instance_type=test_logs_type, slave_instance_type=test_logs_type, num_instances=test_logs_size,bootstrap_actions=[bootstrap_step, heapsize_step],steps=jobsteps)
  File "/home/ec2-user/.etl/lib/python2.7/site-packages/boto/emr/connection.py", line 581, in run_jobflow
    'RunJobFlow', params, RunJobFlowResponse, verb='POST')
  File "/home/ec2-user/.etl/lib/python2.7/site-packages/boto/connection.py", line 1196, in get_object
    raise self.ResponseError(response.status, response.reason, body)
boto.exception.EmrResponseError: EmrResponseError: 505 HTTP Version Not Supported