Revert "Fixed NPE with last commit when biogrid directory did not exist"

This reverts commit 3f3577f6c89e20cd78e1709861f1151438f01e66.
Revert "Added prompt to replace old BioGRID networks installed locally."

This reverts commit 5d1ad7b64556052a6e1737fe4742dc2c286365d6.