Disable Praefect in hook service tests
HookService is called by gitaly-hooks to execute hook logic. Right now, the tests are ran with Praefect in front of the Gitaly. In production, Praefect never proxies HookService calls as HookService is strictly for Gitaly's internal use. This commit disables Praefect in the tests of HookService.
Related to: #4019 (closed)
Edited by Sami Hiltunen