protobuf 3.18.0不兼容

[pingguoilove]

tablestore 5.2.1
protobuf 3.18.0 （指定到3.6.1版本后运行正常）

报错如下：

Traceback (most recent call last):
  File "test_ots.py", line 1, in <module>
    import tablestore
  File "/usr/local/lib/python2.7/site-packages/tablestore/__init__.py", line 115, in <module>
    from tablestore.client import OTSClient
  File "/usr/local/lib/python2.7/site-packages/tablestore/client.py", line 25, in <module>
    from tablestore.protocol import OTSProtocol
  File "/usr/local/lib/python2.7/site-packages/tablestore/protocol.py", line 21, in <module>
    import google.protobuf.text_format as text_format
  File "/usr/local/lib/python2.7/site-packages/google/protobuf/text_format.py", line 52, in <module>
    from google.protobuf.internal import decoder
  File "/usr/local/lib/python2.7/site-packages/google/protobuf/internal/decoder.py", line 87, in <module>
    from google.protobuf.internal import encoder
  File "/usr/local/lib/python2.7/site-packages/google/protobuf/internal/encoder.py", line 71, in <module>
    from google.protobuf.internal import wire_format
  File "/usr/local/lib/python2.7/site-packages/google/protobuf/internal/wire_format.py", line 36, in <module>
    from google.protobuf import descriptor
  File "/usr/local/lib/python2.7/site-packages/google/protobuf/descriptor.py", line 113
    class DescriptorBase(metaclass=DescriptorMetaclass):
                                  ^
SyntaxError: invalid syntax