t7900: prepare for switch of the default strategy
The t7900 test suite is exercising git-maintenance(1) and is thus of course heavily reliant on the exact maintenance strategy. This reliance comes in two flavors: - One test explicitly wants to verify that git-gc(1) is run as part of `git maintenance run`. This test is adapted by explicitly picking the "gc" strategy. - The other tests assume a specific shape of the object database, which is dependent on whether or not we run auto-maintenance before we come to the actual subject under test. These tests are adapted by disabling auto-maintenance. With these changes t7900 passes with both "gc" and "geometric" default strategies. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>