Add restart wait timeout to redis restarts

Summary

Large installs need a large amount of redis memory. This can take a long time (15+ minutes) in some cases.

Proposal

Allow configuring runit service sv_timeout parameter so that a long restart does not crash a reconfigure.

References

From reconfigure:

service[redis] (dynamically defined) had an error: Mixlib::ShellOut::ShellCommandFailed: Expected process to exit with [0], but received '1'
---- Begin output of /opt/gitlab/embedded/bin/chpst -u root:root /opt/gitlab/embedded/bin/sv restart /opt/gitlab/service/redis ----
STDOUT: timeout: run: /opt/gitlab/service/redis: (pid 10834) 13925917s, normally down, got TERM
STDERR: 
---- End output of /opt/gitlab/embedded/bin/chpst -u root:root /opt/gitlab/embedded/bin/sv restart /opt/gitlab/service/redis ----
Ran /opt/gitlab/embedded/bin/chpst -u root:root /opt/gitlab/embedded/bin/sv restart /opt/gitlab/service/redis returned 1

From Redis log

2019-07-11_12:14:25.01841 21846:S 11 Jul 12:14:25.018 * Saving the final RDB snapshot before exiting.
2019-07-11_12:28:05.15658 21846:S 11 Jul 12:28:05.156 * DB saved on disk