Removes check for MongoDB storage engine
Removes check for MongoDB storage engine

We are not relying on WiredTiger-specific metrics anymore, so check for
storage engine can safely be removed.

bureau14/qdb-benchmark,solatis/qdb-benchmark,bureau14/qdb-benchmark,bureau14/qdb-benchmark,solatis/qdb-benchmark,solatis/qdb-benchmark,solatis/qdb-benchmark,bureau14/qdb-benchmark