assert_stderr_clean should exclude JAVA_TOOL_OPTIONS
assert_stderr_clean should exclude JAVA_TOOL_OPTIONS

Patch by David Capwell; reviewed by marcuse for CASSANDRA-15532

closes #56

stef1927/cassandra-dtest,stef1927/cassandra-dtest,pcmanus/cassandra-dtest,blerer/cassandra-dtest,blerer/cassandra-dtest,pauloricardomg/cassandra-dtest,pauloricardomg/cassandra-dtest