Fix logic bug in RiakObjectIdConverter
Fix logic bug in RiakObjectIdConverter

* Missing parenthesis were causing issues for certain objects.


Former-commit-id: 5307af7196b3addcba8b1214d02511da15590927
rob-somerville/riak-dotnet-client,rob-somerville/riak-dotnet-client,basho/riak-dotnet-client,basho/riak-dotnet-client