stress-tests: Check if ssl-scheme is not set before setting it in the params (#895)
stress-tests: Check if ssl-scheme is not set before setting it in the params (#895)

This changes enables run `stress-tests` to clusters with self-signed certificates.
neo4j/neo4j-javascript-driver,neo4j/neo4j-javascript-driver,neo4j/neo4j-javascript-driver,neo4j/neo4j-javascript-driver,neo4j/neo4j-javascript-driver