Avoid Gitaly fail-fast timeouts from Sidekiq
Related to https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/20259 and gitaly#1254 (closed)
For web and api workers, https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/20259 is tuning Gitaly timeouts to be more aggressive.
Since we're making these timeouts more aggressive for time-sensitive workloads, it makes sense to drop them for time-insensitive workloads (ie, Sidekiq).