[master] fix lib import error

[tim-rj]

Signed-off-by: tim-rj sonic_rd@ruijie.com.cn

- What I did
fix sonic-net/sonic-buildimage#5343 import lib error
- How I did it

show interface breakout

- How to verify it

show interface breakout

- Previous command output (if the output of a command-line utility has changed)

root@sonic:/var/core# show interfaces breakout 
Traceback (most recent call last):
  File "/usr/bin/show", line 12, in <module>
    sys.exit(cli())
  File "/usr/lib/python2.7/dist-packages/click/core.py", line 764, in __call__
    return self.main(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/click/core.py", line 717, in main
    rv = self.invoke(ctx)
  File "/usr/lib/python2.7/dist-packages/click/core.py", line 1137, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/usr/lib/python2.7/dist-packages/click/core.py", line 1137, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/usr/lib/python2.7/dist-packages/click/core.py", line 1114, in invoke
    return Command.invoke(self, ctx)
  File "/usr/lib/python2.7/dist-packages/click/core.py", line 956, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/usr/lib/python2.7/dist-packages/click/core.py", line 555, in invoke
    return callback(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/click/decorators.py", line 17, in new_func
    return f(get_current_context(), *args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/show/interfaces/__init__.py", line 118, in breakout
    config_db = ConfigDBConnector()
NameError: global name 'ConfigDBConnector' is not defined

- New command output (if the output of a command-line utility has changed)

no above import error
``

[tim-rj]

any one help forward this, thanks!

[pettershao-ragilenetworks]

help forward this, thanks!