Ever since my system upgraded haproxy to 2.3.10 this test has
consistently timed out. While that would be a breaking change
involving the independent vtest project too, I think the VTC
syslog spec would work better with something like:

    expect skip facility.level regex

Where skip could be uint, * or ? similar to how logexpect works,
and both facility and level could also be * to be non-specific.
For now, let's hope this does not break the test suite for anyone
else.