Use PerRepositoryElector in test-with-praefect
test-with-praefect target runs Gitaly's tests with Praefect in front of them. It's currently using a legacy election strategy. This is not necessary any more as we are setting up a database for the tests. This commit changes the election strategy to 'per_repository' to better test the production setup.
Related to #3485 (closed) as tests fail without these fixes and workaround when integrating !3907 (merged)
Edited by Sami Hiltunen