watcher-tls-test intermittently fails cloning gnocchi from github

Seen here:

http://logs.openstack.org/33/659133/1/check/watcher-tls-test/1329ba9/controller/logs/devstacklog.txt.gz#_2019-05-14_18_36_47_315

2019-05-14 18:34:37.845 | Obtaining gnocchi[keystone,mysql,redis] from git+https://github.com/gnocchixyz/gnocchi#egg=gnocchi[redis,mysql,keystone]
2019-05-14 18:34:37.845 | Cloning https://github.com/gnocchixyz/gnocchi to ./src/gnocchi
2019-05-14 18:36:47.315 | fatal: unable to access 'https://github.com/gnocchixyz/gnocchi/': Failed to connect to github.com port 443: Connection timed out
2019-05-14 18:36:47.334 | Command "git clone -q https://github.com/gnocchixyz/gnocchi /opt/stack/devstack/src/gnocchi" failed with error code 128 in None

This looks pretty rare though:

http://logstash.openstack.org/#dashboard/file/logstash.json?query=message%3A%5C%22fatal%3A%20unable%20to%20access%20'https%3A%2F%2Fgithub.com%2Fgnocchixyz%2Fgnocchi%2F'%3A%20Failed%20to%20connect%20to%20github.com%20port%20443%3A%20Connection%20timed%20out%5C%22%20AND%20tags%3A%5C%22console%5C%22&from=7d

2 hits in 7 days. We can use this to track the bug and if it becomes a problem we could try adding a retry loop or longer timeout. I'm not sure if opendev infra has gnocchi in a mirror somewhere we could use either.

Note that in both cases this shows up it was on the vexxhost-sjc1 node provider.