The `CaptureManager.global_and_fixture_disabled()` context manager (and
`CaptureFixture.disabled()` which calls it) did `suspend(); ...;
resume()` but if the capturing was already suspended, the `resume()`
would resume it when it shouldn't.
This caused caused some messages to be swallowed when `--log-cli` is
used because it uses `global_and_fixture_disabled` when capturing is not
necessarily resumed.
Ran Benita