Tests: Speed up blackbox tests by 1 minute each

The "keep_tunnel_open_time" option adds an unnecessary 60 second delay
to each test (except the tunneling test, where it is necessary). By
setting the time to 0, each test now runs 60 seconds faster.

envs/monkey_zoo/blackbox/config_templates/base_template.py

@@ -13,4 +13,5 @@ class BaseTemplate(ConfigTemplate):
             "HostnameCollector",
         ],
         "monkey.post_breach.post_breach_actions": [],
+        "internal.general.keep_tunnel_open_time": 0,
     }