This diff adds a new sanitizer exception entry to avoid a `vptr` issue
caused by the boost test case timeout in the avalanche unit test
`poll_inflight_timeout`. For some unknown reason this issue only
triggers when building with cmake, and only with clang 7 (8 and 9 are
OK).
It also removes the `abc-p2p-compactblocks` exception to the ubsan build
on CI since this test is now green.