Increase default bootstrap timeout

After switching to mirror.mirantis.com, bootstrap nodes becomes
slower than from upstream. Increase timeout from 8 to 10 min.

Change-Id: I43dc692ee494f4b6ff8ec834f906c2b7b4ae001a
diff --git a/tcp_tests/settings_oslo.py b/tcp_tests/settings_oslo.py
index dbb81ad..dacdb22 100644
--- a/tcp_tests/settings_oslo.py
+++ b/tcp_tests/settings_oslo.py
@@ -95,7 +95,7 @@
                     ext.UNDERLAY_NODE_ROLES.k8s_controller]),
     ct.Cfg('bootstrap_timeout', ct.Integer(),
            help="Timeout of waiting SSH for nodes with specified roles",
-           default=480),
+           default=600),
     ct.Cfg('nameservers', ct.JSONList(),
            help="IP addresses of DNS servers",
            default=[]),