KNOWN_EXCEPTIONS don't include all possible exceptions

oslo.config may raise a ConfigFileValueError when run server.start(***) in `glance/cmd/api.py`, which is a subclass of ValueError so it can be caught using KNOWN_EXCEPTIONS.

But ConfigFileValueError is not in the KNOWN_EXCEPTIONS, use index method of KNOWN_EXCEPTIONS will raise an ValueError, which is unexpected:

```
2017-10-22 22:47:46.460 94 CRITICAL glance [-] Unhandled error: ValueError: tuple.index(x): x not in tuple
2017-10-22 22:47:46.460 94 ERROR glance Traceback (most recent call last):
2017-10-22 22:47:46.460 94 ERROR glance File "/var/lib/kolla/venv/bin/glance-api", line 10, in <module>
2017-10-22 22:47:46.460 94 ERROR glance sys.exit(main())
2017-10-22 22:47:46.460 94 ERROR glance File "/var/lib/kolla/venv/lib/python2.7/site-packages/glance/cmd/api.py", line 92, in main
2017-10-22 22:47:46.460 94 ERROR glance fail(e)
2017-10-22 22:47:46.460 94 ERROR glance File "/var/lib/kolla/venv/lib/python2.7/site-packages/glance/cmd/api.py", line 65, in fail
2017-10-22 22:47:46.460 94 ERROR glance return_code = KNOWN_EXCEPTIONS.index(type(e)) + 1
2017-10-22 22:47:46.460 94 ERROR glance ValueError: tuple.index(x): x not in tuple
2017-10-22 22:47:46.460 94 ERROR glance

```