tests: Add information on how to add Vulture suppressions
tests: Add information on how to add Vulture suppressions

Former-commit-id: e6985b34995408cc6077946d3719e1da8c349888
syscoin/syscoin,syscoin/syscoin2,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin2,syscoin/syscoin2,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin,syscoin/syscoin2,syscoin/syscoin2,syscoin/syscoin,syscoin/syscoin2,syscoin/syscoin