Fixes #236 incorrect error message 'dur' for MongoDB versions 3.2 and above #249
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Links to issue: General MongoDB Error: 'dur' when connecting to mongo 3 #236
If you are running a MongoDB 3.2+ system, then Journal, Journal Commits and Write Data Files won't return any data as it uses WiredTiger as its storage engine, and the service checks fail with a not really meaningful message as the raise a Key error which is not caught.
Resolved that issue by adding a more meaningful error message.