Fix dns timeout for undefined syslog host

On some platforms, inet:getaddr can take several seconds to return when
passed the undefined atom, which is the default value of "syslog_host",
and therefore the value used when running tests. On platforms where it
takes longer to return than the test is allowed to run, the
couch_log_writer_syslog_test will fail with *timed out*.

This short circuits the case when "syslog_host" is undefined, and
removes the race from the test.

1 file changed
tree: f0c56d03dc9fcb538624d65c945f2508f8843895
  1. include/
  2. priv/
  3. src/
  4. test/
  5. .gitignore
  6. .travis.yml
  8. rebar.config