Handle logging configuration exceptions

[sebdah]

I don't want to see this when the logging dir does not exist:

[root@ip-172-31-11-49 ec2-user]# dynamic-dynamodb -c dyndyn.conf
Traceback (most recent call last):
  File "/usr/bin/dynamic-dynamodb", line 22, in <module>
    import dynamic_dynamodb
  File "/usr/lib/python2.6/site-packages/dynamic_dynamodb/__init__.py", line 29, in <module>
    from dynamic_dynamodb.aws import dynamodb
  File "/usr/lib/python2.6/site-packages/dynamic_dynamodb/aws/dynamodb.py", line 13, in <module>
    from dynamic_dynamodb.log_handler import LOGGER as logger
  File "/usr/lib/python2.6/site-packages/dynamic_dynamodb/log_handler.py", line 97, in <module>
    dictconfig.dictConfig(LOG_CONFIG)
  File "/usr/lib/python2.6/site-packages/logutils/dictconfig.py", line 573, in dictConfig
    dictConfigClass(config).configure()
  File "/usr/lib/python2.6/site-packages/logutils/dictconfig.py", line 365, in configure
    '%r: %s' % (name, e))
ValueError: Unable to configure handler 'file': [Errno 2] No such file or directory: '/Users/sebastian/dynamic-dynamodb.log'