Modification of `omnisharp.json` can lead to errors

[nils-a]

As discussed on slack:

... Problem is with case-sensitivity. As I've added manually, I used BakeryPath. Cake extension wants bakeryPath.
... Also, the current logic seems to fail if cake section is missing.

[Tacodiva]

Just ran into this, seems like a pretty big issues.
I was trying to use cake for the first time but had an existing omnisharp.json file without the cake property so I was having a pretty hard time getting intellisense working as the extension would just give me errors with cryptic messages. Would be nice to see this merged :)