Reverting broken change to skip testing in info.asciidoc."

This reverts commit elastic/x-pack-elasticsearch@5e4d77f4cabae98103382604f6a339a796fd7e2b. Original commit: elastic/x-pack-elasticsearch@6dca6d7e9f01db87ba3fc6628adb459719d7134b

Author: debadair

docs/build.gradle

@@ -91,7 +91,6 @@ buildRestTests.expectedUnconvertedCandidates = [
  'en/rest-api/ml/validate-job.asciidoc',
  'en/rest-api/security/authenticate.asciidoc',
  'en/rest-api/watcher/stats.asciidoc',
- 'en/rest-api/info.asciidoc',
  'en/security/authorization.asciidoc',
  'en/security/tribe-clients-integrations/logstash.asciidoc',
  'en/watcher/actions.asciidoc',