Safe mode is deprecated ! use write concern instead

[Frescha]

in logstore mongo the uri default to safe_mode. It is not safe anymore to use this. Write concerns are a mych better way of dealing with consistency. Two parameters are there for this purpose.
First w will check write consistency (write consistencty is about write to mongo node not write to disk)
Second j will check journaling (write to disk).

http://api.mongodb.org/python/2.4.2/api/pymongo/mongo_client.html?highlight=write%20concerns

[Frescha]

shinken-solutions/shinken#758