Fixing reference before assingnement when we dont use all tls related files (#80)

* Fixed multiple TLS tests fail on 2nd test due to tls cert/key filenames being replaced

* Fixing reference before assingnement when we dont use all tls related files

Author: filipecosta90

redis_benchmarks_specification/__runner__/runner.py

@@ -257,6 +257,9 @@ def process_self_contained_coordinator_stream(
                     benchmark_tool_workdir = client_mnt_point
 
                     metadata = {}
+                    test_tls_cacert = None
+                    test_tls_cert = None
+                    test_tls_key = None
                     if tls_enabled:
                         metadata["tls"] = "true"
                         if tls_cert is not None and tls_cert != "":