We observed in a "debug" variant in the tenant_migration_terminate_primary_jscore_passthrough suite that the primary didn't have time to hand off to a caught-up secondary before the primary exceeded waitTimeMillis and died. The resulting error bubbled up to the JS test and caused a BF. Since waitTimeMillis was only 100, it's not surprising that secondaries might occasionally lag for too long in a debug build to permit a clean handoff. Let's increase it.